excessive brake pedal travel

HOW TO FIX EXCESSIVE BRAKE PEDAL TRAVEL

What Is Excessive Brake Pedal Travel?

Excessive brake pedal travel happens when you feel your pedal sinking rapidly while braking, or sitting lower than usual when activating your vehicle’s brakes. This can happen due to wobbly discs knocking pistons back or air in the braking system.

Performing DIY brake repair to fix excessive brake pedal travel can be a tedious task. Follow the steps below to diagnose and repair your sinking brakes.

How to Fix Excessive Brake Pedal Travel

1. Diagnose the Problem . To diagnose issues with the master cylinder, the first thing you need to do is remove the lines, install brass or plastic plugs into the outlets, and apply the brakes. What happens when you apply the brakes will tell you what issue your vehicle is having. You can continue this process of elimination by isolating each wheel.

2. Use Your Parking Brake. If you don’t typically engage your parking brake, the parking brake can be key in figuring out if your car is suffering from excessive brake pedal travel. If the parking brake doesn’t properly engage, that generally means a low pedal.

3. Bleed the Brakes. Bleeding your brakes is an important step in brake pedal travel repair and other brake issues. Use a jelly jar half full of brake fluid and a short hose to depress your brake pedal.

While depressing the pedal, rotate the star wheel to lose up the clearance. Then, go back one click when the wheel scrapes. It’s best to have a partner on hand when bleeding your brakes.

4. Bleed the Master Cylinders . After bleeding the brakes, bleeding the master cylinders is the next step. In traditional systems, you begin with the longest line in the circuit first, and go from the right rear, left rear, right front, and left the front. In diagonally split systems, the order is right rear, left front, left rear, and right front. Flush out the bleeder valves, and finally, remove the air from your master cylinder.

If you’re not sure which type of system your vehicle is or are unaware of the proper tools needed to fix excessive brake pedal travel, it’s best to bring your vehicle into Brake Works.

With two convenient locations with great weekend hours, getting proper brake maintenance is simpler than you think. Contact our team of certified specialists to schedule an appointment.

Erika Suarez

Previous post what problems can old power steering fluid cause, next post best brake pads for trucks, leave a reply cancel reply.

Save my name, email, and website in this browser for the next time I comment.

Brake Works is a family owned and operated brake and auto repair business, established in 1989 by Ray and Eddie Gruetzner. We are committed to providing the highest quality brake and auto repair service possible at affordable prices.

Our Services

Best Brake Shop In San Antonio Suspension Repair San Antonio Car AC Repair - San Antonio Auto Repair Shop San Antonio

Hours of Operation

14950 Nacogdoches | 210-657-3300 | San Antonio, TX | [email protected]| Copyright © 2023. Brake Works. All rights reserved.

• Brake Repair and Replacement Service
• Suspension Repair Service
• Car AC Repair Service
• Auto Repair Service

CALL US TODAY (210) 657-3300

Get an appointment

CONTACT FORM

June 2019 Issue

Abnormal brake pedal diagnosis.

By Roy Dennis Ripple

A customer may complain of a brake pedal that ‘feels funny.’ It's your job to determine whether it’s due to aerated and/or contaminated brake fluid, excessive pedal travel or any other cause.

Vehicles normally respond to our commands in a fairly predictable manner. When we push on the accelerator, we go forward; when we turn the steering wheel, we change direction; and when we press the brake pedal, we stop. Of all the things we ask of our vehicles, “please stop” is the most important request. The brake pedal should give the driver a reassuring feel that says, “I got this.”

The brake pedal is the driver’s physical connection to the brake system, providing feedback that the driver uses to determine if there’s a problem with his brakes. Spongy, mushy and squishy are just a few of the terms that a customer might use to describe negative brake pedal feedback. Sometimes these concerns can be tricky to diagnose due to the numerous failures that can cause an unacceptable brake pedal feel.

The first step in diagnosing a low brake pedal concern is to determine the type of low brake pedal issue you’re dealing with, and if other symptoms are present. It might be a good idea to forgo the road if you’re uncomfortable with the function of the brakes and settle for a parking lot cruise instead.

Besides a low or mushy pedal, note if the brakes pull, squeak or pulsate. Does the pedal slowly drift to the floor when at a stop, or does it stop solid, but too close to the floor? Determine if one or more wheels are locking up, and note if the red or amber brake warning lamps are illuminated. All of this information will aid in your diagnosis.

A low brake pedal is always caused by either a hydraulic or a mechanical malfunction. When a mechanical malfunction is the cause, it’s due to a component moving past the range of motion for which it was designed. A good example of this is out-of-adjustment rear brake shoes. The universally accepted specification for brake shoe-to-drum clearance is .015 in. Every thousandth of an inch over spec causes excess brake pedal travel. Less than .025 in. travel at the master cylinder pushrod can equal about ½ in. at the pedal. Every little bit of unnecessary movement adds up.

Another example is a caliper piston that retracts too far into the bore when disengaged. Rear calipers with integral parking brakes are notorious for this. This causes the piston to travel further than designed to initiate contact between the inboard pad and the rotor. This excess travel can translate into a heap of movement at the brake pedal.

Hydraulic concerns present the biggest challenge in low brake pedal diagnosis. The smallest amount of air trapped anywhere in the system will have a big effect on brake pedal feel. Brake fluid converts the energy applied to the pedal into the force required to engage the brakes. This happens because fluids are compressible only to a very small degree, so any pressure applied to a liquid is transferred to all portions of the liquid and to the walls of the container it occupies. Since air is very compressible, air creates a nice, soft cushion for the fluid to lean on, ruining any chance of achieving solid hydraulic pressure.

Use the information you acquired during the road test to guide your initial visual inspection. Watch all the calipers move while an assistant pumps the brake pedal. Worn caliper pins or incorrectly installed brake pads can cause the caliper to flex side to side. This lateral movement uses up brake pedal travel. Be cautious of brake pads that are location-specific, or that need to line up with a locating pin during installation. If these pads are incorrectly installed, they’ll cause the caliper to flex.

While you’re eyeballing the calipers, make sure they’re on the correct side. When a caliper is installed on the wrong side, the bleeder valve will be below the inlet. Since air rises to the top, good luck bleeding that caliper. Check meticulously for an external leak. Brake fluid leaks don’t always present themselves as drops that puddle in the driveway. Just a little seepage at a fitting can cause big trouble at the pedal. Don’t forget to look behind the wheel cylinder boots while checking for leaks; there should be no fluid there.

During your visual inspection, also watch the rubber hoses as a helper pumps the brake pedal. Look for a bulge in the hose that appears under pressure, then disappears when the pedal is released. I’ve seen hoses twist while pressurized due to a defect at the union where the rubber hose meets the metal crimp. Excess hose movement causes excess pedal movement.

Most negative brake pedal feedback issues fall into one or more of the following categories:

•A pedal that stops hard at the bottom but has excess play at the top is usually the result of a master cylinder or pushrod issue. •A pedal that’s spongy or mushy can be caused by air intrusion, contaminated brake fluid or a mechanical component moving beyond its designed range of motion. •A pedal that continues to move toward the floor when applied is caused by a loss of hydraulic pressure, which can be caused by an external leak or an internally leaking component. Contaminated brake fluid can also cause a brake pedal to drift downward.

An occasional exception to these rules—there’s always an exception—is the antilock brake system (ABS) hydraulic control unit (HCU). A defective HCU will create symptoms that feel like air intrusion or a pressure loss and can really complicate your diagnosis.

Let’s look at a brake pedal that stops hard at the bottom but has excess play at the top. A good way to determine if there’s too much pushrod travel is to loosen the master cylinder-to-power booster attaching hardware. Have an assistant hold the loose master cylinder firmly against the booster while you slowly apply the brake pedal. Determine how far the pedal moves before your helper feels the push on the master cylinder. Excessive pushrod play could be caused by a weak or broken master cylinder bore spring that’s not returning the piston all the way to the back of the bore, or it could be a pushrod or booster issue. Remember, a little play at the pushrod is a lot at the pedal.

Many automakers use an adjustable pushrod. This adjustment is set at the factory and shouldn’t have to be messed with. If you need to adjust the pushrod, something’s wrong.

We once serviced a Ford Escape with excessive brake pedal travel at the top. Loosening the master cylinder determined that we lost about 3 in. of pedal travel before the piston moved. We removed the master cylinder and discovered that the small dome-shaped piece that was pressed into the end of the pushrod, which fits into the master cylinder bore, was missing, and laying at the bottom of the booster. This added almost ¼ in. of travel to the pushrod.

Diagnosing a spongy, mushy brake pedal issue can sometimes be frustrating as well as time-consuming. Here’s an example of how important the initial road test is when diagnosing a spongy brake pedal.

While we were road-testing a vehicle with a low, spongy brake pedal, we noticed that the brakes pulled to the left. That told us that the left front and right front calipers were not applying evenly. Using the results from the road test, we started our visual inspection at the front calipers. Both front wheels were spinning freely and both stopped spinning when the brakes were applied. There was no excessive movement in either caliper or hose during brake application, and the brake pads were a healthy 9mm, with nice, beefy rotors.

Since the road test suggested there was an issue with the front brakes, it only made sense to check the front calipers for air. We removed a nice pocket of air from the right front caliper, which temporarily fixed the pedal. I say “temporarily” because we found no reason for that caliper to be holding air, as there was no sign that it was recently disassembled. Caliper piston seals and wheel cylinder cup seals can replicate a one-way check valve. Fluid can’t get out but air can get in. So we replaced the caliper. This scenario reinforces the importance of gathering information during the road test. If we didn’t feel the brake pull, we wouldn’t have started our diagnosis at the front calipers.

Unfortunately, it’s not always that simple. If you’re faced with a low, mushy pedal and the visual inspection yields no clues, it’s time to break out the blockers. Blocking off sections of the brake system (not individual components) is the surest way to find the cause of the problem. Thexton Manufacturing makes a master cylinder plug kit (Part No. 803P) that can also be used on HCUs. It’s important to use quality plugs when blocking brake pressure. A small leak at a plug will yield erroneous results.

Always start by blocking the master cylinder ports. If the master cylinder is good, the pedal should be rock hard—barely moving—with the ports blocked. If the brake pedal moves at all, the master cylinder is leaking internally, there’s a pushrod issue or the brake fluid is contaminated.

If the master cylinder is good, most diagnostic procedures recommend blocking the HCU ports next. The problem is that the HCU tends to be hard to access, and the fittings are usually tough to get a wrench on due to their proximity to each other. So in the spirit of streamlined diagnosis, it makes sense to check the easier-to-access components first, which would be the wheels.

Block each wheel individually at the steel line, before the rubber hose; this way, you’re taking the hoses, calipers and wheel cylinders out of the equation. Do not block off the calipers by using vise grips to crimp the rubber hoses. Damaging a rubber brake hose could cause it to work like a one-way valve, allowing pressure to be applied to the caliper but not to bleed off, causing a perpetually applied brake caliper. The Thexton block-off kit contains only male fittings, and you need a female fitting to block the steel line. Attaching a brass union to the male plug works great. Test the pedal after blocking each wheel. We found a right rear caliper on a Ford Explorer that was causing a low, spongy pedal using this method. We never did identify the actual cause of the caliper malfunction. It wasn't leaking, the pins were sturdy, no air, all looked fine. But the pedal came right up when we blocked it off. We replaced it; problem fixed.

If you find no problem at the wheels, you’ll need to access the HCU. It’s best to block all the outlet ports on the HCU at the same time. This is a lot of work just for a diagnosis, but at this point there’s very little choice.

If the pedal is still low with all the HCU outlet ports blocked, before passing sentence on the HCU, perform a service bleed. HCUs seem to be a favorite resting place for stowaway air. Even if you have no reason to believe that the brake system was opened to atmosphere, you should bleed the HCU before condemning it.

ABS service bleed procedures are performed with a scan tool and vary by manufacturer. Some procedures are as easy as pressing the brake pedal a few times and clicking a button on the scan tool; others will require you to open bleeder valves, which makes a real mess on the shop floor. Whatever the procedure, it’s very important to bleed all the wheels after performing an ABS service bleed.

I started using a brake pressure bleeder a couple of years ago and I’ll never go back to the old pedal-pumping method. Pressure bleeders work great. They attach to the master cylinder reservoir in place of the cap and put the brake system under consistent pressure. The biggest advantage of this—besides not needing an assistant—is that you can open a bleeder valve and just let it flow, pushing all of the air out of a line from the master cylinder to the wheel cylinder or caliper with just one turn of a bleed er valve. If you don’t already have a pressure bleeder, I highly recommend getting one.

It’s important to properly benchbleed a new master cylinder before installation. It can be tough to bleed the air from a master cylinder once it’s installed on the vehicle. Mount the master cylinder firmly in a vise and screw bleeder fittings into the outlet ports. Attach hoses to the fittings, with the other ends of the hoses in the reservoir, submerged in brake fluid. An effective kit for bench-bleeding a master cylinder comes with check valves, which allow the air to be pushed out while not allowing air to get sucked in on the back stroke. Thexton, Dorman, NAPA and others offer such kits.

If you don’t have check valves for the hoses, the procedure will still work. Since the hoses are submerged in brake fluid, fluid from the reservoir rather than air will be pulled back into the master cylinder. The problem is that air that doesn’t make it to the end of the hose gets sucked back into the cylinder on the back stroke. Check valves prevent this from happening.

With the hoses in place, slowly push the piston into the master cylinder, then allow the piston to return to the rest position. You’ll see air bubbles exit the master cylinder through the clear hoses. Do not push the piston past its normal range of motion; doing so can damage the piston seals, rendering the master cylinder useless. When using check valves, all the air is gone within seven to ten strokes. Be sure that the fittings are tight, as a poor seal at a fitting will pull air into the master cylinder.

The heart of a hydraulic brake system is the fluid, and when that goes bad, so does the pedal. Most automotive applications use DOT 3, DOT 4 or DOT 5.1 fluid, all of which are glycol-ether-based. DOT 5 is silicone-based and should not be mixed with glycol-based brake fluids. The most important property of brake fluid is that it maintains a stable viscosity and compressibility throughout its entire operating temperature range—very cold to very hot. The negative property of brake fluid is that it’s hygroscopic, which means it absorbs water.

Water in brake fluid greatly lowers its boiling point. The dry boiling point of DOT 3 is 401ºF. The wet boiling point, defined by the temperature at which the fluid boils after absorbing 3.7% water by volume, is 285ºF. Big difference. Since brake fluid temperatures at the calipers can easily exceed 200ºF, this could be a problem. The fact that water freezes also tends to complicate things a bit. This is why it’s recommended that brake fluid be changed every two years.

When brake fluid is contaminated with water it turns a darker color. If the brake fluid looks contaminated, or if you’re diagnosing a vehicle that’s more than two years old, recommend a brake fluid flush. Use a pressure bleeder or brake fluid flush machine to push all the old fluid out through the bleeder valves. Be sure to check all the bleeder valves before selling the brake flush. If you think the valves are going to break off, you need to know this beforehand.

A couple of more things: A customer might describe an intermittent false ABS activation event as a low brake pedal. But if the pedal feels fine to you, check for DTCs in the ABS module. Also, contaminated fluid can damage an HCU. Brake fluid is designed to protect metal brake parts against corrosion, an attribute it loses when weakened by water. So when replacing an HCU, it’s imperative to flush the fluid.

It seems that the furthest thing from anyone’s mind as he’s driving down the road is the brake system. The song on the radio or the setting of the climate control system occupy more brain space than the brakes do. So maybe problems like a low brake pedal and/or noisy brakes should be looked upon as an important safety warning. It’s the brake system whispering, “Hey, remember me?” to the procrastinator who should plan on getting his brakes checked very soon.

Articles This Month

Editor’s report, trouble shooter, trade secrets, foreign service, driveability corner, succession planning: will your business survive you, tools of the trade, other articles of interest, 'bright idea' for short detection.

By Thomas R. Tillman

Sometimes you get lucky, and the location of a circuit that’s shorted to ground is easy to find. But the rest of the time, a systematic approach must be used to make short work of the problem.

No results found.

Dealing With A Low Brake Pedal

"Honey, can I borrow your car?" No problem. She tosses you the keys. But at the first stop sign you draw a startled breath--the pedal's going, going, almost gone! There's even a little dent in the carpet under the pedal. Didn't she notice? Well, no she didn't. Typically, low-pedal trouble develops so gradually that people don't realize it.

Hydraulic brakes have been around since Duesenberg introduced them in 1921, but apparently a long history is no defense against troubles. And professionals and do-it-yourselfers alike are often guilty of misdiagnosis--they blame the master cylinder, though it is seldom the culprit.

There are only two plausible reasons for a low pedal: air in the system; and excessive movement between linings and rotors or drums (due to lack of adjustment, an out-of-round drum, or a wobbly disc that's knocking the pistons back so that there's extra space to take up before braking action begins).

Isolation You can find out all you need to know about the master cylinder by removing the lines, screwing brass or plastic plugs into the outlets, and then applying the brakes. If the pedal's high and hard now, the master has been properly bled and its seals are okay. The pedal would sink gradually if it were bypassing--that is, if fluid were finding its way around the sliding seals. You've also confirmed that the booster is okay. Reattach the lines.

Continue the process of elimination by clamping hoses to isolate each wheel. Use a suitable rounded-jaw tool, either the locking-pliers type or one of those inexpensive J-hooks with a knurled screw. Releasing one at a time should locate the problem.

Use That Parking Brake If you never engage the parking brake, self-adjustment of the pads and rotor simply won't occur, and that means a low pedal. Another impediment to adjustment is corrosion and contamination of the piston, cylinder and self-adjustment hardware. So, change your habits and start using the parking brake every time you leave the car, and overhaul or replace those calipers if they're not just right. If the parking brake isn't used regularly, one of these days a parking lot attendant will apply it and your car will be immobilized until those corroded cables and other seized parts are replaced.

Beat The Drums Rear drum brakes can cause a low pedal, too. Seized star-wheel screws and otherwise inoperative self-adjusters are practically an epidemic, and you're risking trouble if you don't replace the hardware when replacing shoes. At the very least, clean the star-wheel threads and treat them to a coating of antiseize compound.

There's another factor that's usually not recognized: drivers who never stop aggressively enough in Reverse to ratchet the self-adjusters. It's a good idea to stomp on the brake pedal every week or so while backing up--preferably in a deserted lot or other safe place.

What about the drums themselves? They're frequently out of round, leaving excess shoe-to-drum clearance and, of course, causing pulsation.

The old-fashioned, low-tech way to bleed brakes is to use a jelly jar half full of brake fluid, a short piece of hose, and a patient helper to depress the brake pedal.

Depress the tab while you rotate the star wheel to close up the clearance. When the wheel scrapes lightly, go back one click.

Brake drums will be marked clearly as to how far they can be machined safely to remove out of round.

Bubble Trouble For all practical purposes, brake fluid is incompressible. Air, on the other hand, can be squeezed down into a smaller-than-natural volume, and its presence will disrupt the operation of any hydraulic system. It promotes internal corrosion, too. Ergo, it must be expelled.

The most common cause of pedal problems is failure to bench bleed a new master cylinder. Screw the supplied fittings into the outlets and place the tips of the tubes in the fluid in the reservoir. Clamp one of the master's mounting ears in a vise--don't grip around the cylinder--so the unit is as level as possible. Use a rod or drift to stroke the piston slowly. Wait at least 15 seconds between strokes to allow the low-pressure chamber to release all its bubbles and fill completely. Keep stroking until there's no more evidence of air at the ports and tube tips.

If the car has a replacement cylinder that somebody didn't bench bleed, you might be able to do it with the master in place, provided you can jack the rear of the vehicle high enough to get the cylinder to be level. Again, pump slowly and allow time between strokes.

An important precaution to observe during any bleeding procedure that involves pumping the pedal is to limit pedal travel. You don't want the delicate lips of the master cylinder's piston seals to ride so deep in the bore that they encounter rough corrosion or deposits, which can scratch them. Just throw a chunk of 2 x 4 on the floor under the pedal.

When it comes to the bleeders at the wheels, most people just open them and let the fluid squirt. Not only will this result in slippery puddles on the floor, the fluid can shoot farther than you might expect--think about the 2500-plus psi of line pressure on some ABS-equipped cars. Brake fluid is a pretty effective paint remover, and it really burns when you get it in your eye. Wear eye protection.

One convenient setup is a tube and transparent bottle kept half full of fresh fluid. There are also inexpensive 1-man bleeder hoses that contain a 1-way valve to eliminate the possibility of air being drawn back in when you release the pedal.

The bleeder cups and hoses that are often included in manual vacuum pump kits, such as those from Mighty Vac, work well. Once again, you can see what you're getting, and you don't have to keep climbing into the seat to pump the pedal.

You should also be aware of special procedures. For example, on Teves Mark II ABS systems, you can't get fluid to the rear brakes unless you turn the key on and then apply the pedal slightly. Be sure to check the shop manual if your vehicle has an antilock braking system.

Finally, there's the bleeding sequence. Since you're supposed to do the longest line in the circuit first, the traditional order is right rear, left rear, right front and left front. But with the diagonally split systems you'll find mostly on fwd cars, the order is right rear, left front, left rear then right front. ABS-equipped cars may have special procedures to follow.

Bubbles collecting in high spots in the brake system need to be removed by opening the bleeder valves to flush them out.

Bench bleed a master cylinder to get air out before installing it into the vehicle.

How It Works: The Dual Master Cylinder

Whether you call it the dual, split or tandem master cylinder, it has been used on every car sold in this country since 1967, although Cadillac had it in '62. Even so, most people don't understand its construction and operation. A typical modern specimen is of the composite variety--aluminum with a plastic reservoir--but iron 1-piece units are still around on older vehicles. Two pistons ride in the bore, and here's where we encounter some potentially confusing terminology. The rear piston is the primary, the one in the front is the secondary. This apparent misnaming resulted because the rear piston is the first to receive the signal from the brake pedal, so it does make a certain amount of sense. Kind of. Each piston has a primary cup seal at its front and a secondary at its rear. In normal braking, the pushrod from the booster forces the primary piston forward. No pressure is created until the primary seal covers the compensating or vent port from the reservoir, but once it does fluid is trapped in the chamber between the pistons and it becomes a solid column. Pressure is routed from this chamber to two wheels. A combination of the trapped fluid and the primary piston coil spring bears on the secondary piston, to which the line to the other two wheels is attached. The replenishing ports allow fluid to move freely between the chambers behind both pistons' primary cups and the reservoir, determined by demand and expansion and contraction from temperature changes. If a hose lets go or a saboteur has sawed through one of the brake lines, the other half will still provide a means of decelerating the vehicle, albeit with a lower pedal and reduced stopping power. This protective function is, of course, the dual master's reason for being.

This Portable Jump Starter Is 26% Off on Amazon

The Best Labor Day Tire Sales of 2024

Automotive Touch Up Paint 101

The 8 Best Portable Jump Starters

The Best Carports for Weather Protection

The Best Car Waxes to Protect Your Paint Job

Score the Best Portable Jump Starter for 41% Off

The Best Car Vacuums

Tesla's FSD Software May Be Too Good To Be True

The Best Car Battery Chargers to Buy Now

The 7 Best Jumper Cables for Your Car

The 6 Best Car Sun Shades

Choose country

• United Kingdom
• United States

Search results

Find a manual, troubleshooting: common brake issues and causes, you are here.

Troubleshooting your car's brakes is actually pretty easy, and is simply the result of having the right knowledge combined with an intelligent, systematic approach. And once you've worked out what's wrong, fixing it is often easy with the help of your Haynes manual .

The brakes on your car are probably the most important system, and due to the difficult job they do and how often they are used, they are also one of the most likely to wear and need service. Even when everything is working properly with your brakes, and nothing is worn out, they can suddenly start making disconcerting noises or develop a shudder under use. Modern cars use a power assist (vacuum or otherwise) hydraulic system, with disc brakes on the front wheels, and discs or drums on the back. All modern cars come with sophisticated antilock braking systems (ABS) and brake based stability control, which complicates some aspects of troubleshooting and repair, but those systems will inform you when there is a problem and default to the old, simple system. There is also typically a separate, mechanical parking/emergency brake, either cable or electrically operated, that works only on the rear wheels.

Before we get into the specifics of brakes and their problems, you may want to look at some of the basic rules for troubleshooting in general, as written in the beginning of every Haynes manual: Troubleshooting 101

Much like our earlier examination of clutch issues, there are two general failure modes for brakes: They aren't engaging well enough, or they aren't disengaging. Then there are minor issues such as brake squealing, brake shudder/pulsing, burning smells, leaking fluids, pulling to one side, etc.

Brakes not working well

Even today, your brakes can fail completely, but there are failsafes built into the system to prevent that from happening in most cases. Every car since 1968 has had redundant hydraulic systems, not to mention the parking/emergency brake, to prevent complete brake failure. The master cylinder actually contains two pistons and seals, which in simpler systems controlled the front and back brakes separately, or the diagonally opposite wheels, so at worse you would only lose half your brakes.

Soft Pedal  - The brake pedal is easy to push but there is less braking.

• Low brake fluid
• Air in brake fluid
• Bad master cylinder
• Bad caliper/wheel cylinder
• Blown brake line
• Bad residual valve
• Fluid leak in system
• Boiled brake fluid
• Bad wheel bearing

The first thing to check with any brake issue is the fluid level and condition in the master cylinder reservoir. If there is a leak somewhere the fluid level may be so low as to make even the redundant system ineffective. If there is fluid, but it is below the full indication, that may indicate that the friction material on the pads or shoes,or the rotors or drums themselves, may be worn beyond effectiveness.

If there is plenty of fluid in evidence, check if it is hot; repeated hard use, towing, descending a steep hill, or a dragging caliper can boil the fluid. DOT 3 brake fluid should not boil until it gets above 400 degrees Fahrenheit, but old brake fluid that has absorbed water can boil at as little as 284 degrees, which is why it needs to be changed every other year.

Brake hydraulics are a sealed system, so there should not be air in the lines, but if after service you have a sponge pedal that is the most likely cause. A bad master cylinder can introduce air into the lines, as can a failure at a caliper or wheel cylinder. The residual valve (often in the master cylinder or proportioning valve) keeps a small amount of pressure in the brake lines so the pedal doesn't have to travel so far until initial engagement; a failure here can be difficult to pinpoint.

Another uncommon cause of a soft pedal and long travel, is a bad wheel bearing, which is unrelated to the brakes except for being in the vicinity of the rotors. The failing bearing allows the hub to move around, effectively pushing the brake pads back into the caliper as far as it can.

Hard Pedal  - It takes much more pressure to get the same amount of pedal travel and braking force.

• Bad power booster
• Vacuum hose leak
• Bad check valve
• Collapsed vacuum hose
• Seized caliper
• Extremely worn brake pads

Most instances of a hard pedal come down to a failure in the power boost system, whether vacuum based or hydro-boost (used mostly on diesels, we won't be covering it here). The power booster uses engine vacuum to assist your leg when applying the brakes, and is nearly universal in modern cars. If it the booster, check valve, or vacuum hose is bad, it will likely also cause a vacuum leak and rough engine idle as well, but an engine with a bad valve or head gasket can also cause low vacuum which can effect the brake boost.

Another cause of a hard brake pedal can be a brake caliper that is stuck or seized. Typically a seized caliper or pads will cause a burning smell, a pull to one side, and dragging at one wheel, but it is possible for it to stick without those, and effectively lessening your braking by nearly half (if it is a front wheel, which provide 75% of the braking). Wearing your pads down to the metal baking plates will also result in a very "wooden" brake pedal as well, as there is not as much friction when it is metal on metal, and they have to clamp harder to slow you down; the horrible grinding noise is usually an indication before the hard pedal.

Brakes hanging up/dragging

The other major way brakes act up is when they fail to disengage completely in one way or another. A common symptom of this type of braking issue is a burning smell from the amount of heat the hung up brake generates. Seldom does this result in a car that won't move at all, but driving with the brakes dragging is unsafe and will result in even more damage in a short amount of time if not repaired.

Some of the cause of brakes dragging on one or more wheels can be:

• Seized caliper/pads
• Seized parking brake cable
• Rusted rotor/drum
• Clogged master cylinder return hole
• Pinched/collapsed brake line

A seized caliper or brake pads that have become jammed in the caliper is probably the most common failure of this type, and can occur due to age, rust, and salt used on winter roads. Luckily, changing a brake caliper is not a hard job, and can be accomplished in about an hour. The same factors can cause cable operated parking brakes to jam up as well, requiring a replacement of the parking brake cable. The way to prevent these issues is to avoid driving in deep puddles, or areas where salt is used on the roads, but if that isn't an option, be sure to clean the wheels and underside of the car often in winter.

Typically rusted rotors or drums only happen when a car has been sitting for a long period. If you are trying to bring a project car back to life, but can't get it to roll, chances are this is the problem.

A clogged fluid return hole in the master cylinder can cause all four wheels to drag, because the fluid sent to the wheels when you press the pedal can't return and let the pressure off. In a similar vein, a pinched hard brake line, or a rubber line that has started to come apart internally can cause the same problem, though localized to one or two wheels.

Other brake issues

• Shudder/vibration/pulsing under hard or repeated braking - This is caused by warped/bent rotors, or sometimes just from a localized buildup of pad material on the rotor surface. Resurfacing the rotors, grinding them smooth and flat again, can fix the issue if it isn't too bad, but often warped rotors got that way because they were overheated, and they will warp again when heated.
• Squealing/howling/squeaking noise  - Typically, an annoying high pitched noise coming from the brakes is the metal "wear indicator" tabs, meant to alert you when there is less than 25% of the pad left. Sometimes brakes can become noisy because of a glaze on the pads from stop and go traffic, which can be fixed with a few hard applications of the brakes to clean it off. Finally, because of the different friction materials, manufacturer tolerances, and random wear factors, pads can suddenly start making noise because they resonate in the range they vibrate at during use. Anti-squeal paste tries to fix this by sticking the pad to the caliper piston, raising the resonance outside of this range.
• Sinking pedal  - If while sitting at a stop you find the pedal slowly sinking to the floor with your foot on it, you have a master cylinder that is just starting to go bad, or a leak somewhere in the system. But if no leak can be found, it is most likely just one of the rubber seals withing the master cylinder allowing fluid and pressure to sneak by.

Recommended for you

Latest Tips & Tutorials

GMC Sierra Soft Brake Pedal: Causes + How to Fix

Dealing with a soft brake pedal on your GMC Sierra can be dangerous and frustrating. You should absolutely not drive your truck until you track down the problem.

While tracking down the problem sounds daunting, there’s a lot you can do at home to get a hard pedal.

One possible cause of a soft brake pedal in the GMC Sierra could be air trapped in the brake lines. Your brake system should remain closed, meaning air shouldn’t get inside.

However, air can get trapped in the brake lines, especially after service. Another potential issue could be related to the ABS pump. A failing ABS pump can sometimes cause a low brake pedal.

Causes of Soft Brake Pedal in GMC Sierra

Brake Fluid Leak (Air in the System)

One possible cause of a soft brake pedal in your GMC Sierra could be a brake fluid leak. If the leak occurs in the brake lines or connections, air will enter the lines.

Unlike brake fluid, air can be compressed, creating a spongy or soft pedal feel. The soft feeling is air compressing before the brake fluid moves.

To determine if there is a brake fluid leak, carefully inspect for any indications of dampness or fluid presence in the vicinity of brake lines, fittings, and calipers. These areas are likely to be the source of the issue.

• If you’ve recently installed a new master cylinder in your Sierra, you’ll need to bench-bleed it to remove all the air from the system.
• A blown brake line can cause a very soft pedal. You will get the brake warning light if the pressure is too low. There will be brake fluid everywhere under the vehicle, and the change would have been instant.
• Open the master cylinder. Is the fluid level in the normal spot? Is it low? Do you see any air bubbles in? Tap it gently with a socket extension and see if any air bubbles rise.

Defective Master Cylinder

A defective brake master cylinder can be another reason for a soft brake pedal in the GMC Sierra. When you press the pedal down, it is responsible for generating hydraulic pressure for the brake system.

If it is bad, the brake pedal might feel soft or spongy.

Inspect the master cylinder for signs of damage or wear, and consider replacing it if necessary. If you need to replace it, don’t forget to bench-bleed it.

Worn Out Brake Pads

Worn brake pads can also contribute to a soft brake pedal because there’s more distance for the piston to travel when pressing the pad into the rotor.

Check your GMC Sierra’s brake pads for signs of wear and replace them if needed to ensure proper brake performance. This can easily be done at home by pulling one of the front wheels.

Poorly Adjusted Rear Drums (If Equipped)

If your GMC Sierra is equipped with rear drum brakes, poor adjustment can lead to a soft brake pedal.

Inadequate drum brake adjustment can cause the shoes to be too far from the drum and, in turn, lead to a spongy pedal. Properly adjusting the rear drum brakes can alleviate this issue.

• Most drums or self-adjusting when stopping in reverse.

Compromised Brake Booster

A compromised brake booster can also result in a soft brake pedal. The brake booster assists in applying force to your Sierra’s master cylinder, and a failure in this component can lead to reduced braking performance.

Inspect the brake booster for signs of damage or malfunction, and consider replacement if needed.

What Happens When You Push The Brake Pedal (Understanding the Braking System)

When you push the brake pedal in your GMC Sierra, you initiate a series of events in the braking system that helps to slow down or stop your truck.

Understanding the basic principles of this system can help you diagnose common issues, such as a soft brake pedal.

At first, pressing the brake pedal creates mechanical force, which is transferred to your Sierra’s master cylinder. The master cylinder then transforms that force into hydraulic pressure within the brake lines.

This hydraulic pressure activates the brake calipers, which in turn, apply force to the brake pads. The brake pads make contact with the brake rotors, generating friction and heat, ultimately slowing down the wheel and your vehicle.

Your GMC Sierra’s brake system operates efficiently due to incompressible brake fluid that transmits 100% of the force applied to the brake pedal to all four brakes. However, when there’s air in the system, it becomes compressible and leads to a soft brake pedal.

Keep in mind that properly functioning brake fluid is critical to the overall operation of the braking system. Over time, brake fluid can become contaminated or lose its effectiveness, which can lead to a soft or spongy brake pedal.

Regularly checking and replacing brake fluid, as recommended by your vehicle’s manufacturer, will help maintain the efficiency of your Sierra’s braking system.

Maintaining the condition of brake components such as rotors, pads, and calipers is also important, as worn or damaged parts can negatively impact the performance of the braking system.

Regular inspections and timely replacement of these components can help prevent soft brake pedal issues and ensure the safety of you and your passengers.

Diagnosing Soft Brake Pedal Issues

When you experience a soft brake pedal in your GMC Sierra, it could be due to several causes. Firstly, make sure you inspect the brake lines for any air bubbles. Air in brake lines can lead to a spongy pedal feeling and affect fluid circulation.

To diagnose common brake issues, follow these steps:

• Check for air in brake lines:  Start by bleeding the brake lines to release any trapped air. It’s a good idea to perform a brake fluid change if it hasn’t been done recently, as old fluid can contribute to the issue.
• Examine the master cylinder:  A worn or leaking master cylinder could also be the culprit. Look for visible brake fluid leaks and ensure the brake warning light is not on. If there’s a leak or the master cylinder is in poor condition, it should be replaced.
• Inspect brake pads and rotors:  Improperly installed or worn brake pads and rotors can cause your Sierra’s brake pedal to feel soft. Check your front and rear brake pads, ensuring they are in good condition and installed correctly.

Remember, addressing any issues as they arise will help you maintain your GMC Sierra’s braking system more efficiently and ensure your safety on the road.

Prevention and Maintenance Recommendations

To maintain optimal performance and prevent soft brake pedal issues in your GMC Sierra, follow these recommendations.

Regular brake fluid replacement:  One of the major causes of a spongy brake pedal is air in the brake lines. To prevent this issue, be sure to replace your brake fluid as recommended by GMC.

Inspect brake lines:  Over time, rubber brake lines can degrade and cause a soft brake pedal. Regularly inspect your brake lines for cracks, bulges, or other signs of wear. Replace them as needed to maintain proper braking performance.

Bleed your brakes:  Whenever you service your brakes or replace the brake fluid, be sure to bleed the brake system. This process removes air bubbles from the lines, ensuring a firm pedal feel.

Proper brake pad installation:  When changing your brake pads, be sure to follow proper installation procedures to avoid air entering the brake system. Check your owner’s manual or consult a professional technician for guidance.

Addressing master cylinder issues:  In some cases, a malfunctioning brake master cylinder can cause a soft pedal feel. If you suspect a problem with the master cylinder, have it inspected and replaced by a qualified technician.

By following these preventive measures and conducting regular maintenance on your GMC Sierra’s braking system, you can help ensure optimal performance, safety, and longevity.

Should You Drive Your GMC Sierra With a Soft Brake Pedal?

It is generally not advisable to drive with a soft brake pedal , as it can pose serious safety risks for you and other road users. A soft brake pedal may not provide sufficient braking power, leading to longer stopping distances and potentially causing accidents.

While it may not always be an immediate emergency, it is crucial to address the issue as soon as possible.

To ensure your safety and maintain your vehicle’s optimal performance, it’s best to consult a professional mechanic or a GMC service center when you notice a soft brake pedal.

They will have the knowledge and tools to inspect your vehicle, determine the root cause, and recommend the appropriate repairs or adjustments. Don’t put yourself or others at risk by driving with a compromised braking system; address any issues immediately and prioritize your safety on the road.

Share this:

• Forum Listing
• Marketplace
• Advanced Search
• Gen 3: 2005-2009

brake pedal travel

• Add to quote

So I recently got this car and have replaced rotors and pads but not touched the hydraulics. Fluid level is good and the color is still pretty clear. The brakes work well and have decent feel. The weird thing is at a stop the pedal goes basically all the way to the floor. It doesn't just fall at a steady rate, but if I push hard after I've stopped it goes down further. It never releases the brake, the car never rolls and if I drive it feels fine. Is this normal with these vehicles or is the master starting to go on me? I know different cars have different pedal feel. Just curious what others have noticed.  

Subarus are known to have spongy brake pedal, my 3rd gen is similar. I also just replaced brakes and had a soft pedal after removing some fluid because of compressing all 6 pistons. I was worried about having to bleed them at first. After letting idle and pumping the brakes a few times it improved. Now after about 200 miles it feels great. It is still a bit on the soft side for my liking but some of that is likely firewall flex, a common complaint with all Subarus in addition to spongy pedal. There are master cylinder brace kits available to help alleviate the issue, which can get worse with spirited driving and extreme braking duties. How long ago was brake service done? Were they bled? Is it better or worse than before?  

No bleeding from me, I don't think the PO did anything. It was basically out of rear brakes when I bought it and the fronts where half gone. I'm sure the PO had pads thrown on the front and that's it.  

I've had several Subies but mostly high performance models IE STis and WRX and they've never felt quite like this. My old 99 outback is kinda crappy on the brakes but that's because they're tiny. LOL  

• ?            
• 198.9K members

Top Contributors this Month

• Forum Listing
• Marketplace
• Advanced Search
• Jeep Grand Cherokee & Commander Forums
• WJ Grand Cherokee Forum

Brake Pedal Travel

• Add to quote

I just replaced pads and rotors on my son's 01. The brake pedal seems to have way to much travel in it compared to the other vehicles we have. I checked the brake cylinders for leaks - none. The only thing I can think of is, 2 years ago he was in the DC area for the summer and the front caliper chocked and we had to have a shop replace. I am beginning to think they didn't bleed them properly? I asked him when the excessive travel in the pedal started and he he doesn't recall. I am thinking I'll bleed them again and see if there is an improvement. My other though is the master cylinder is going bad? Any thoughts/past experience on this matter? Thanks, Tim  

If I'm going to replace the pads and rotors I'll also replace the calipers, especially living in the salt/rust belt. I did a complete brake job on my 04 about 5-6 years ago then had to replace the front calipers, pads, and rotors again last year mainly do to the right front caliper locking up. When doing the first caliper replacement I let the master cylinder go dry which was likely a mistake. In using my Motive power bleeder and manual bleed procedures I had one heck of a time getting all the air out of the master cylinder. At least I bled all the old fluid out while adding new but have never seen so much of a problem getting the trapped air out of the MC. Did a master cylinder bench bleed about 3 times off my WJ then finally ended up doing a bench bleed while it was attached to the brake booster. Believe I'd start by bleeding all all the calipers and pushing all the old fluid out while never letting the MC reservoir go dry. Good luck.  

The OP's vehicle may be old enough for rubber brake lines to collapse, interfering with return pressure? My '98 developed that issue a couple years ago, so it may be time for the OP to replace rubber hoses.  

Try bleeding it first making sure all air is out of the system. If you still have a low pedal, replacing the master cylinder is good advice.  

Are your rear brakes disc or drum? As I recall the WJ could come either way. If it has drums, your rear shoes are probably out of adjustment. That causes a lot of pedal travel.  

This. ^^ Check your rear brakes whether or not it's drum or disc.  

On mine the rears are disc. I believe it does have rubber brake lines but I did take a look at them when I was in each wheel area and they looked OK but who knows when under pressure. I am going to bleed them and see what happens, if it doesn't resolve it I'll move to the next step. Thanks guys for all your input. I'll update on this as I go. Tim  

plimbob said: On mine the rears are disc. I believe it does have rubber brake lines but I did take a look at them when I was in each wheel area and they looked OK but who knows when under pressure. I am going to bleed them and see what happens, if it doesn't resolve it I'll move to the next step. Thanks guys for all your input. I'll update on this as I go. Tim Click to expand...

I had a bad ABS module. The mechanic replaced it with a used one. The pedal now travels a long way before the brakes catch. They thought that the master cylinder was bad, so they replaced that. The pedal travel is still so long it feels more like a clutch pedal. They said that they bled it 3 times with a scan tool to operate the ABS pump while bleeding. What can I do to fix this?  

You've added a new question to someone else's thread. While not a horrible thing to do, it's probably best to make your own if you can. Otherwise, we'll need more info such as ...what vehicle is this for?  

I have a 2001 grand cherokee with a 4.0L. Sorry about hijacking someone's thread. Sent from my SM-G781U using Tapatalk  

b 4 and after brake work and bleeding as good as i can, my pedal has always been soft. car stops great so i call it ok. check rotor temp with ir gun after coasting to stop. all about the same,not hot!! i find a place where i can drive ? a mile with no brakes. coast to stop. rotors should be cold...no drag.  

If it is the master cylinder it will get worse and you will have to change it. If the vehicle stops fine now it may be ok. I don't think WJ's have excessive brake pedal travel compered to other vehicles.  

• ?            
• 18.6M posts
• 741.9K members

Top Contributors this Month

• Forum Listing
• Advanced Search
• Tundra Discussion
• Problems: Maintenance, Warranty, Repair, Issues

Excessive Brake Pedal Travel

• Add to quote

I've come across a few others with the same issue of excessive brake pedal travel. 2013 DC, pedal slowly crept closer and closer to the floor over the past few months and I have tried bleeding at least 5 times without any improvement. I have used the 2 person method, vacuum bleeding, techstream air bleeding, nothing has made any bit of improvement. To describe it better, the pedal sinks almost all the way to the floor before the brakes grab. There is no loss of pressure if sitting at a stop light as though the MC seals where bad and allowing fluid to bypass. As with what I have read with others, 1 primer pump before braking makes it feel normal. At this point my only guess is a stuck dump valve in the ABS modulator. With the truck off, pumping the pedal will NEVER result in a rock solid pedal, not sure if this is normal? Any other car I have worked with including my wife's 2014 corolla, when the car is off you get 2 or 3 pumps before the pedal is rock solid. When hooked to techstream I can actuate all the abs solenoids and the pedal get rock hard. This leads me to believe that the problem exists int the ABS modulator or further down the line. Does anyone know which solenoids are which? SFLH, SFLR, SRRH, SRRR, SFRH, SFRR, SRLH, SRLR are the 8, I'm assuming 4 inlet and 4 dump, but which are which? The pedal acts the same when moving or stopped leading me to believe that a warped rotor or bad wheel bearing are not a factor.  

I assume you have new pads? I can't imagine anything being actually being "stuck" in the ABS and computer not registering an error. There maybe something leaking and introducing air into the system.  

There is a section in the Service Manual that details checking the Actuator Motor. It talks of activating the ABS solenoids with tech stream. This what it says in the 2015 manual. I assume it is the same for 2013 (SFRH) and ABS Solenoid (SFRR) being RIGHT Front wheel.... LEFT Front wheel LH: ABS Solenoid (SFLH), ABS Solenoid (SFLR) RIGHT Rear wheel RH: ABS Solenoid (SRRH), ABS Solenoid (SRRR) LEFT Rear wheel LH: ABS Solenoid (SRLH), ABS Solenoid (SRLR)  

Not new pads, but checked them and they still have around 50% life left in them. It's very possible something is introducing air into the system, I am not super familiar with the tundra braking system, but with the pedal being solid when solenoids are closed I'm assuming I can rule out the MC. Not sure where the accumulator lies in the equation... Thank you for the info on the solenoids, I can mess with the truck tonight and see if I can isolate the softness in the pedal to one wheels set of solenoids. As far as being "stuck" I guess my my theory is more of the valve is functioning, but not seating properly in the valve body due to rust, debris or just wear, and allowing some fluid to bypass the dump and cycle around.  

I'm in the same boat as you when i bought the truck in July the brakes felt great but have gotten softer since then. I've done stainless brake lines,rebuilt front calipers,installed OE front brake pads and did multiple bleeds with tech stream with a pressure bleeder and the two man procedure with no help.I was thinking Master or air in the ABS that i can't out with tech stream.My next step is unbolting the calipers and bleeding them in different orientations and i'm still trying to find 12mm X 1mm plugs to plug off the master to test it.With the truck off and the vacuum bleed out of the booster i still have about a 1 1/4 of travel before then pedal get hard.Judging by the size of the master that is a fair amount of hydraulic travel before the pedal gets hard but i can not get a cutaway of whats truly in this master. If you push on the brake pedal and cycle the ABS dump valves the pedal should go to the floor as it fills the accumulators in the ABS unit all four of mine acted the same so it seems like the abs unit is fine.But the last ABS i messed with was in my 97 Chevy suburban.  

Well, have not been able to isolate the issue to any one set of solenoids. For the heck of it I dropped it off at the dealer just to see what they would say. Of course they say master cylinder (saw that coming), also say that front calipers are seized (not buying that) and need to be replaced, front rotors resurfaced, new front pads, and new rear rotors and pads....to the tune of $1800 and change.....no thanks. At this point I figure I will go ahead and start with new rotors and pads, and while I am down there and really check out the calipers and seals, clean grease everything, etc. I'm assuming nothing will change, so I'll probably replace the master as well just for kicks. If nothing changes at that point, I would have to assume that the only thing left would be the ABS Module, unless there is something else in the brake system I am missing. Just frustrating that it seems so many people have what I consider to be the EXACT same issue, and I have yet to see anyone with a definitive solution.  

One thing you could maybe check is your wheel bearing... I know it's a completely different animal, but I know in the ATV world, if you have to pump your brakes to make them hard, with no air in the system, nothing else out of the ordinary, if the wheel bearing is going bad, the rotor can tend to push the caliper piston back in, then, when it comes time to hit the brakes, you basically have to "take up the slack" again. Just a thought.  

• ?            
• 162.7K members

Top Contributors this Month

• Forum Listing
• Marketplace
• Advanced Search
• Toyota Truck, SUV and Van Forums
• Highlander Forum
• Highlander 1st Generation (2001-2007)

Brakes - Excesive Pedal Travel, HELP!

• Add to quote

I have an '02 6 cyl FWD. I 've recently noticed there is excessive brake pedal travel, goes all the way to the floor, when braking. The fluid level is fine, just below Max. I also checked the front pads they are fine, probably between 50-75% remaining on the pads. I have not bled the brakes as there should not be a reason for air in the lines. Anyone have any ideas?  

pedal I would suspect your brake master cylinder, but I would still suggest bleeding, but you are right, it's unlikely air would just now decide to enter. I assume you have checked for leaks around your disk brake calipers?  

lqueral said: I would suspect your brake master cylinder, but I would still suggest bleeding, but you are right, it's unlikely air would just now decide to enter. I assume you have checked for leaks around your disk brake calipers? Click to expand...

I have a 2004 - It has always done it  

master . The only thing about a leak is that the fluid was not that low. How tough are master cylinders to replace on a Highlander?[/quote] The master can be leaking internally, past the piston seal, so fluid would not actually escape to the outside. I haven't done a HL master, as mine is an 05 with 22k, but it should be straightforward, although there can be some special bleeding procedures to follow or the piston inside the master might not end up centered within it's bore, leading to perhaps a brake or ABS warning light. If you explore this forum, there are service manuals for HL's available for dloading, and I would recommend that you follow the bleeding procedure described within.  

ajwilkens said: I have an '02 6 cyl FWD. I 've recently noticed there is excessive brake pedal travel, goes all the way to the floor, when braking. The fluid level is fine, just below Max. I also checked the front pads they are fine, probably between 50-75% remaining on the pads. I have not bled the brakes as there should not be a reason for air in the lines. Anyone have any ideas? Click to expand...

• ?            
• 614.3K members

Top Contributors this Month

Log in or Sign up

• Search titles only

Separate names with a comma.

• Search this thread only
• Display results as threads

Useful Searches

• Recent Posts

You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser .

Welcome to Tacoma World!

• Participate in all Tacoma discussion topics
• Communicate privately with other Tacoma owners from around the world
• Post your own photos in our Members Gallery
• Access all special features of the site

Excessive brake pedal travel

Discussion in ' 2nd Gen. Tacomas (2005-2015) ' started by Sweetleu417 , Apr 5, 2017 .

#1 Sweetleu417 [OP] Member

My brake pedal on my 2008 Tacoma seems to have a lot of travel. I've drove other ones and those brake pedals don't travel as much as mine. It's not spongy and parking brake works. Does the shoes have to be adjusted? Anyone else have this problem and with adjusting them it fixes the problem?  

#2 boostedka Well-Known Member

I would say adjust your shoes. 9 times outta ten that's the issue. Then bleed them after if it's still spongy. If your fluid is black, you should flush them anyways  

#3 TheCookieMonster cookies!!!!!!!!!!!

might want to check the brake pad wear front and back,adjust rears, bleed system  

#4 b_r_o Gnar doggy

AFTER YOU ARE CERTAIN that the rear shoes are snug and the fluid is clean and properly bled, you can tighten the pushrod travel under the dash at the pedal. This is always done carefully! Make small changes and then test drive.. Go farther if needed.. .  

#5 L J Well-Known Member

If you pump the brake and the travel decreases it could be front wheel bearings.  

#6 Blacktaco2042 Well-Known Member

check the calipers and make sure that then arent frozen that will cause that too  

#7 TexasWhiteIce Well-Known Member

This happens to me too... I've pretty much checked everything people have mentioned and everything looks good. It's been that way for me since I bought the truck new back in 2010. I've come to the conclusion that's just how it is  

#8 Sweetleu417 [OP] Member

I will get under there this weekend and check everything mentioned.  

#9 taco2010trd Cyber Bully

Tcomaboy said: ↑ This happens to me too... I've pretty much checked everything people have mentioned and everything looks good. It's been that way for me since I bought the truck new back in 2010. I've come to the conclusion that's just how it is Click to expand...

#10 Sweetleu417 [OP] Member

Well I bought 2 cans of brake cleaner. Pulled the drums off sprayed everything off nice and clean And they were way out of adjustment. Adjusted them to where I could just get the drum on. Now the pedal has a lot shorter travel!  

#11 boostedka Well-Known Member

NIce! Good to hear it ended up being a simple fix!  

#12 Doughnut Spaghetti Well-Known Member

Like these guys said, make sure you don't have any leaks and check your pad wear. But yeah, probably just need to bleed your system. May have some air in it.  

#13 seahog Member

The brake pedal in my 2013 4-door Extended Cab, 4-cylinder Prerunner (odometer: 19,000 miles) (have owned it 5 years this October) has the exact same excessive travel issue. If I press the pedal hard enough it will hit the floor (but that takes a lot of force). The "on the road" braking quality is satisfactory, no pulling either left or right. ABS will activate with substantial pedal effort applied, will lock-up at 2-3 mph. I finished performing all of the following in an attempt to reduce the excessive brake pedal travel (the complete brake system has never been touched before): 1.) Bled all four wheel positions - the brake fluid was crystal clear (I'm very impressed, fluid is five years old) with zero bubbles 2.) Front brake pads: -removed, inspected, cleaned them - minimal pad wear, smooth wear on rotors -(No sliders, four caliper pistons on each wheel - wow! Go Toyota!) 3.) Rear brake drums: -Removed drums and all internal components -I needed to manually operate the drum brake shoe automatic adjusters to move shoes away form drums to allow drum removal -Used bolt holes in drums to install bolts which enabled break-away of drums from axle hubs (first time I have seen that great feature - God Bless Toyota!) -Drums, shoes: cleaned, inspected - very smooth, minimal wear on drums, shoes (shoes still have factory machining marks on ends of linings because of minimal wear, but shoes DO have wear) -Blew away brake dust in drums and on backer plates and all components -Six backer plate and shoe contact points: cleaned, lightly lubed with Syl Glyde -Automatic adjusters: disassembled, cleaned, lubed with Syl Glyde -Removed drum gasket material from drums/hubs and installed new gaskets (applied synthetic oil to gaskets to minimize adhesion to surfaces, and possibly allow reuse) -After reassembly I did numerous backups to activate the drum brake shoe automatic adjusters. After too many hour of needless work, the excessive brake pedal travel remains absolutely unchanged. After some miles are added to the linings/pads to reseat them, maybe the excessive travel will decrease - but I doubt that will happen. My 2013 Honda Civic Hybrid which has 27,000 miles has perfect, minimal brake pedal travel AND excellent brake performance. What's up with my 2013 Tacoma which I am proud of - except for the excessive brake pedal travel which I don't like? Please help me resolve this issue without me having to throw $$$ at the Dealership, which I wonder if they would be able to correct.  

#14 bluezzy Love My SuperCharged 07 Sport!

seahog said: ↑ The brake pedal in my 2013 4-door Extended Cab, 4-cylinder Prerunner (odometer: 19,000 miles) (have owned it 5 years this October) has the exact same excessive travel issue. If I press the pedal hard enough it will hit the floor (but that takes a lot of force). The "on the road" braking quality is satisfactory, no pulling either left or right. ABS will activate with substantial pedal effort applied, will lock-up at 2-3 mph. I finished performing all of the following in an attempt to reduce the excessive brake pedal travel (the complete brake system has never been touched before): 1.) Bled all four wheel positions - the brake fluid was crystal clear (I'm very impressed, fluid is five years old) with zero bubbles 2.) Front brake pads: -removed, inspected, cleaned them - minimal pad wear, smooth wear on rotors -(No sliders, four caliper pistons on each wheel - wow! Go Toyota!) 3.) Rear brake drums: -Removed drums and all internal components -I needed to manually operate the drum brake shoe automatic adjusters to move shoes away form drums to allow drum removal -Used bolt holes in drums to install bolts which enabled break-away of drums from axle hubs (first time I have seen that great feature - God Bless Toyota!) -Drums, shoes: cleaned, inspected - very smooth, minimal wear on drums, shoes (shoes still have factory machining marks on ends of linings because of minimal wear, but shoes DO have wear) -Blew away brake dust in drums and on backer plates and all components -Six backer plate and shoe contact points: cleaned, lightly lubed with Syl Glyde -Automatic adjusters: disassembled, cleaned, lubed with Syl Glyde -Removed drum gasket material from drums/hubs and installed new gaskets (applied synthetic oil to gaskets to minimize adhesion to surfaces, and possibly allow reuse) -After reassembly I did numerous backups to activate the drum brake shoe automatic adjusters. After too many hour of needless work, the excessive brake pedal travel remains absolutely unchanged. After some miles are added to the linings/pads to reseat them, maybe the excessive travel will decrease - but I doubt that will happen. My 2013 Honda Civic Hybrid which has 27,000 miles has perfect, minimal brake pedal travel AND excellent brake performance. What's up with my 2013 Tacoma which I am proud of - except for the excessive brake pedal travel which I don't like? Please help me resolve this issue without me having to throw $$$ at the Dealership, which I wonder if they would be able to correct. Click to expand...

#15 WillyJam Well-Known Member

Are you going OEM or AFTERMARKET?  

#16 Jimmyh Well-Known Member

#17 bluezzy Love My SuperCharged 07 Sport!

Jimmyh said: ↑ If you properly adjust the rear brakes the pedal travel should clear up. This is from the Field Service Manual: ADJUST REAR DRUM BRAKE SHOE CLEARANCE (a) Provisionally install the hub nuts. (To hold the brake drum in place) (b) Remove the hole plug, and turn the adjuster to expand the shoe until the drum locks . (c) Using a screwdriver, release the adjuster 15 notches . (d) Install the hole plug. Click to expand...

#18 Jimmyh Well-Known Member

It could be... If in doubt however it could be checked and adjusted in an hour or two if you are slow.  

Products Discussed in Entire Site Forum: 2nd Gen. Tacomas (2005-2015)

• No, create an account now.
• Yes, my password is:
• Forgot your password?

• Forum Listing
• Marketplace
• Advanced Search
• General Service and Repair

Brake pedal travel

• Add to quote

Have a 2011 Heritage The rear brake pedal has way to much travel , I know this is a problem but what is the fix for it.  

Does your bike have ABS ?  

no it don't have ABS  

My 2011 Heritage has ABS Sent from my SM-G900V using Tapatalk  

OK then I would try bleeding the rear brake at the caliper.  

was thinking of that but don't know how air would get in unless fluid is low I don't see a leak Going to switch out the fluid when I try this I see it is needed every 2 years  

Someone could have changed the brake light switch and gotten air in the system.  

Plenty of material left on the rear pads? Is the caliper freed up and operating normally?  

Check your pad thickness. It can be done on the bike with a flashlight and some contortion or mirror. I forgot the spec. HD uses for min. thickness, but it is about the thickness of a credit card! I replace mine way before that.  

I don't know if you bought a used or new Bike or how many miles the Breaks have on them. Most people use the Rear Break to stop. Me I use the Front because it's a lot easier to replace the PADS in the Front. Anyway to much travel is the first sign you need to check the Brake Pads. Probably your a few miles away from hearing the Rotors grinding. First I would Pull those Pads off and check them. When Harley assembles the bikes they put the right amount of Fluid in the Reservoirs, as the Break Pads ware the Fluid level will go down in the Reservoir causing Travel. If you fill up the Reservoir and you need new brake pads, you will not be able to compress the Brake Caliper Hydrophilic Plunger. Also to accomplish that task use a big C Clamp. That's what I would do, Good Luck!  

Ok I changed the fluid in the rear brakes and used a brake bleader pump on it. I have brakes I did notice when the pump was sucking out the old fluid that a single air bubble Had to be the problem How it got in there thow I have no clue. Thanks guys It a easy fix and now ill be changing the fluid out once a year The fluid was bad looked stringy I know I have never changed it in the 3 years I had the bike. Now should the front fluid be changed also It works fine but is old fluid also. Thanks again for the advice and tips  

Yes do the front and avoid problems down the road.  

Harley spec is to change fluid every 2 years. There's even a note about it related to the abs recall, that if brakes are not flushed every 2 years, the abs recall is basically voided (may have this wrong, so check the info for yourself). If you've owned the bike for 3 years, then change the front fluid and check pads while you're down there. From my 2014 service manual, min pad thickness is 16 thousandths. Eff that, that's way too thin! Sent from my SM-G950U using Tapatalk  

• ?            
• 104.1K members

Top Contributors this Month

• Forum Listing
• Marketplace
• Advanced Search
• VOLKSWAGEN passenger vehicles out of production
• Golf 6 (type 5K) 2009 - 2012

Brake pedal excessive travel

• Add to quote

Read some of the threads re above. Brakes have been bled thoroughly following the procedure here on the forum. But still same problem. Is there any way to check for problems with master cylinder and or the servo ? Thanks in anticipation Kenny  

You have pressure bled the system with a diagnostic system in basic settings mode?  

I'm using an aftermarket pressure bleeder but don't have VW diagnostic software and bleeding system. Would you recommend getting this done. ?  

It is impossible to get the system air free without being able to run basic settings.  

Okay thanks will have to get done and I will get back to the forum with the outcome Kenny  

How many times do o through the cycle of ABS bleeding ie, does the program tell you when you have completed the front brake lines and to move to the rear brake lines. Kenny  

On the older Mk20 system it was a 17 step process but on the Mk60 it is open ended so we do three. We also go around the car triggering the basic settings for each wheel and then bleed again but that could be me being obsessive, I am sort of prone to that.  

Thanks Crasher for your reply Sorry but what do you mean by a three step process Excuse my ignorance but VW methods are new to me. Kenny  

We have only ever done this with VCDS so I cannot speak for other systems. Taking your car as an example with the later Mk60 pump (2009/10 we’re very unreliable) you need the following. 1) Car off the floor on all four corners with the wheels off 2) The battery on charge with a good sized charger as the pump takes a lot of current 3) VCDS or similar which allows basic settings 4) A large brake fluid bottle and hose, preferably two 5) A pressure brake bleeder with 1 Bar regulated delivery with a couple of litres fluid 6) An assistant 7) 11mm brake bleed nipple socket or 11mm ring spanner Firstly, we go around all four callipers and let the pressure bleeder run a 1/4 litre per caliper each and at the same time in address 03, output test 3 lets the ABS pump run whilstthe person in the car presses the pedal down and back up ten times. The output test will probably time out and you may need to exit address 04, cycle the ignition, renter 03 and carry on. Then select BasicSettings 04 where VCDS gives you a menu and you select bleeding. You follow the on screen instructions which tells you to hold down the pedal and keep it firmly pressed and after a few seconds the pedal will come back at you with such force that to fight it lifts your bum out the seat but if you don’t fight it, there may be damage, never tried it! The the screen will tell you to shout to your assistant “open” and then press the pedal 10 times and hold the another click makes the pump run for a few seconds and then shout ”close”. You can do this as many times as you like, we do it three times. After this we the operate all four corners in output tests which runs the pump, locks the individual calliper it says and then opens the circuit even though you have pressed the pedal and then locks the calliper. Then you should conduct a road test in a safe place where the brakes can be applied hard enough to trigger the ABS. If you haven’t done the output tests this can bring back excess pedal travel and it is back to bleeding again! I supposed I should do video of how we do it and put it on You Tube but I hate the sound of my own voice and people who show themselves in videos tend to be narcissistic. I think I have covered everything, ask questions if not.  

Crasher said: I think I have covered everything, ask questions if not. Click to expand...

Crasher thanks for the reply, I've got VCDS set up so will follow your instructions. I think a you tube video would be a great idea, you could get an assistant to do the voice over!  

You could also ask why it is only ATE design pumps that need this when the almost identical looking Bosch design doesn’t?  

With VCDS it comes up in the display exactly what to do.  

Okay, just to make sure I have understood you when doing the output test on ABS when it says press pedal, pump the pedal 10 times. I've done the ABS module through basic settings where it says press pedal 10 times in the instructions etc. Have never done it through output test. I have checked a version VW workshop manual for the braking bleeding procedure but nothing there about bleeding ABS. Thanks once again for your patience. Kenny  

We only do the pressure bleed output tests because I think it helps, it isn't official.  

Okay Thanks will reply when done  

Okay quick update, Abs pump bled and further bleeding of system with power bleeder and a noticeable improvement with brakes but still not perfect.  

Do it again  

I was planning to, from ABS pump to double bleed of rear brakes followed by each corner using power bleeder.  

• Could it be air entering the system?
• Brakes not properly bled as I doubt they did this bleeding procedure with the software as previous post suggested?
• Caliper pins not sliding?
• but on the other hand when the brakes are working, they bite pretty sharply.
• Master cylinder problem?
• but then the brake fluid should be again low or I am missing something?
• I tested it with the engine off - 3 times pump the pedal - engine on - it sinks - engine off - 3 times pump the pedal - it becomes stiff pedal

Thanks. This is what I was thinking as well. I thought for a second again this morning that the brakes bite pretty well when the pedal is working, the fluid reservoir is full therefore no leaks, the disk and breaks pads have some life in them(logic confirmed by the bite). When the brakes are not working the pedal sinks half way, the car starts to stop and I need to press again the pedal for the brakes to fully engage therefore it must be something related to air or master cylinder or calipers issue. Will start with the basic settings pressure bleed. Thanks again.  

I will book a brake fluid change with VAG specialist as they don't seem to offer basic settings pressure bleed. They said there is no need to do this, they are pressure bleeding with software only if they change an abs pump. They will do a brake fluid change with the pressure machine without attaching any VCDS software or running the basic settings pressure bleed. Do you think this is correct?  

If air has somehow got into the ABS pump then you could run a 205 Litre drum of fluid through there and not get the air out, it is a peculiarity of ATE Mk20 onwards pumps.  

• ?            
• 178.8K posts
• 43.7K members

Top Contributors this Month

• Forum Listing
• Marketplace
• Advanced Search
• Mercedes-Benz Roadster Forums
• R129 SL-Class

Excess brake pedal travel

• Add to quote

This topic may have been covered numerous times, but with the new sucktastic forum software that won't let us seach individual forums, who know? Anyway, my brake pedal feels like you have to push it 1-2 inches before the brakes grab. I had my local shop look into it. They said the brakes worked normally once you push through the dead travel range. No issues with the fluid or vacuum. They said they think there might be some mechanical adjustability in the brake pedal mechanism, but they weren't sure. Has anyone else experienced a "dead zone" in their brake pedal?  

Yes, my 1995 SL320 has the same problem. Checked by my MB mechanic and found no obvious problem with brakes. However, I do not believe this to be normal for the brakes. My 1985 500SEL brakes respond at a much higher, normal pedal.  

I own a couple of W210s and have owned four W124s and a W201. None of them exhibit the long travel before engagement. I resorted to using google to search this forum, and found a previous thread. Sounds as though it is a common R129 "quirk." Brake Pedal Travel  

Check the brake master cylinder.  

I have this very same problem. I purchased SS brake lines, a brand new master cylinder and brake booster that works on the SL500/SL600 until MY98. After that the brakes were perfect to the touch. However, I traveled for a week and when I came back, I found the brakes suffering from dead travel again. Every time I bleed the brakes, they feel good but not great for a day or so and then they get spongy again. Maybe I have an internal problem in one or more of my calipers. My next target to solve this and get better braking would be to update to the 99+ brembo brakes and silver arrow rotors with 99+ SS brake lines again from Goodrich.  

Just to let you know, I upgraded to the Silver Arrow cross drilled zimmerman rotors and techstar pads. No change in travel.  

Do you have steel brake lines or the oem rubber ones? The reason I'm expecting a change in travel is because I think there might be something wrong with one or more of my calipers. After bleeding them, they would feel good for a day or two, then they start feeling spongy again and need re-bleeding. That is my assessment since everything else is brand new. And if I was to change the calipers, might as well get the upgraded Brembos. Isn't your car a 1999 model? You should already have the big brembo calipers with 234mm brake disc upfront and 300mm in the rear. My 1991 has the smaller 300mm upfront and 278mm in the rear. So I should feel more of a brake upgrade when changing.  

Excessive brake pedal travel is an inherent issue with the R129. This was a very common complaint at the dealerships when the R129's were new. I had a 1995 SL500 years ago, same issue. Thorgod  

Thorgod said: Excessive brake pedal travel is an inherent issue with the R129. This was a very common complaint at the dealerships when the R129's were new. I had a 1995 SL500 years ago, same issue. Thorgod Click to expand...

Click on the 3 vertical dots on the top right of the page and you will see the Search feature for individual forums.  

Of course! Perfectly intuitive! It isn't. Thanks for the tip.  

For what it's worth I just had my brakes refreshed with new fluid, SS lines, EBC red pads, and Zimmerman rotors. This significantly reduced my brake pad travel and improved feel.  

This past weekend I finally got around to putting new brakes on the '99 SL500: Zimmerman rotors and Akebono pads. The dead travel seems to be gone now. What isn't gone is is the mushy feeling and the lengthy pedal travel. At least I can now feel the brakes grab before the pedal travels an inch or two. I don't know why M-B designed the SL's this way. All the other Benzes I have owned had a really firm pedal feel.  

Mine possesses none of those issues. The symptoms you describe typically come from poorly bleeded brake lines/water in brake fluid.  

my 97 R129 and 97 E420 have ENTIRELY different brake feel. E420 has very short travel but not easy to modulate. R129 has long travel and is very easy to modulate. Later models had "brake assist" that with fast application increased brake pad pressure. The tradeoff is do you want "instant" brakes that are hard to modulate or brakes that can easily be modulated, or something in between. I'd like something in between.  

I have a W210 E430 and a 1996 R129 SL500 so I know exactly what you mean ;-)  

Obviously no one can know how your brake pedal feels; when I got my SL 8 years ago I was aware of a long travel before the brakes caught; now I don't even notice it.  

• ?            
• 715K members

Top Contributors this Month