GMC Sierra owners have reported 27 problems related to brake master cylinder (under the service brakes category).
I was traveling on I-95 south in virginia on the hov lanes at about 1:30 pm approaching the route 1 exit. Traffic was dead stopped in front of a moderate flow of traffic and everyone quickly slammed the brakes (including me) to slow and stop to prevent rear ending the stopped cars. Traffic was flowing at approximately 75 mph when I slammed my brakes. The brakes grabbed momentarily and then I heard a loud pop and the brake pedal went to the floor; the vehicle brakes were gone. No pressure was at the pedal even as I pumped it. The only way out was to hit the should and berm and take the route 1 exit to coast to a stop; which I did. No fluid loss was evident at the master cylinder reservoir and I couldn't see evidence of a blown line or brake caliper until I got the vehicle home and noticed the metal (steel) brake line between the master cylinder and the anti-lock brake control valve/module was leaking at a pit in the line caused by rust. The point was under the driver side floor pan on the outside of the frame and parallel with the frame. It blew a rusted pitted spot on the line under pressure.
See all problems of the 2001 GMC Sierra.
While driving my vehicle I was stopping and the brakes were shot. I had to push the pedal as hard as possible to the floor to get it to stop. Luckily I narrowly avoided an accident with the person in front of me. I took the truck to get looked at and the break lines are leaking from the master cylinder to the abs unit. They are extremely rusted and they need to be replaced. The estimate was over $1000.
See all problems of the 1999 GMC Sierra.
Metal brake lines rusted causing brakes to fail and replacement of master cylinder and brake lines.
The problem is a totally rusted-out set of steel brake lines throughout the GMC truck. The burst brake line is in the engine compartment. It is the line that runs from the antilock brake distribution point (attached to the frame beneath the driver seat). It runs along the frame, above the frame rail and past the steering box, and then makes a right turn beneath the radiator to the passenger side of the truck, where it exits into the wheel well and connects to the flexible brake hose on the passenger side. The steel line burst in the area adjacent to the steering box, so that it sprays brake fluid all over the steering box whenever the brake pedal is depressed. This quickly emptied the reservoir on the master cylinder leaving almost no brakes at all. There is very minimal braking available with the pedal fully depressed the floor. I initially examined the system to see if there is any chance of a do-it-yourself repair but quickly abandoned that idea. All of the brake lines are badly corroded and covered with scale, so there is no chance of cutting out the bad segment, double flaring the ends, and splicing-in a short segment to replace the rusted-out portion of the brake line. All of the brake lines throughout the truck are badly rusted and likely will fail again if left in place (according to the GMC service manager). The brake line that failed burst in a part of the engine compartment that would seem to not even be exposed to road salt, since it is inside the engine compartment and relatively shielded from salt spray and road grime by the body, wheel well and frame rail. The dealer service manager in murphy, nc estimates that it will take one of his mechanics almost a full day to remove all of the bad brake lines and fabricate replacements (these lines are not available in prefabricated form from GMC.
See all problems of the 2005 GMC Sierra.
While on an errand there seemed to be a sudden, extreme decrease in braking ability. We were still able to stop with brake to the floor if we allowed plenty of time to do so, however, it felt very unsafe to drive. Upon a mechanic's inspection it was determined that the group of brake lines from the abs to master cylinder were completely rusted through and needed to be replaced. The total cost of repairs was $684. 95.
Complete hydraulic brake failure without warning. Check engine light only came on after the vehicle was stopped with the emergency brake. The dealer said that the front brake had stopped working sometime ago, only the rear brake had been working. The dealer "replaced rear pads and rotors and parking brake shoes, found four busted brake lines, replace all front brake lines, master cylinder to abs module (2) and from module to front brakes(2). ".
See all problems of the 2000 GMC Sierra.
Rigid brake lines from the master cylinder to the abs module rusted through causing a catastrophic failure of the hydraulic brake system.
See all problems of the 2004 GMC Sierra.
2006 Sierra denali with just over 75,000 miles. With 1/2 block warning and only traveling at a speed of 20mph, I was unable to come to a complete stop. The brake pedal was all of the way to the floor when I ran into a van in the intersection. I felt very little resistance from the pedal and the abs definitely did not go off. There was no snow or ice on the road surface. However after towing the vehicle to the local dealership, I was told nothing was wrong with the truck. Two independent third parties have suggested this could be a master cylinder issue even though GMC gave it a clean bill of health.
See all problems of the 2006 GMC Sierra.
While applying the brakes, the brake pedal went to the floor. The vehicle braking power was diminished and the braking distance was substantially increased. Had another vehicle or structure been in front of my truck there would have an accident with airbag deployment and injuries. A visual inspection of the braking system by this writer revealed a ruptured brake line. The area of the rupture as well as the balance of the suspect brake line was in poor condition due to corrosion. The remaining brake lines were found in a similar corroded condition. The corroded condition was found on the entire length of the brake lines up to within 6" of the master cylinder. The corrosion was also in areas including what this writer would consider "protected areas".
Tl- the contact owns a 2005 GMC Sierra. The contact stated that while driving at various speeds, she applied the brakes and the vehicle slid a small distance. The contact then pumped the brakes and the brakes functioned normally. The vehicle was taken to an independent mechanic for diagnosis and the contact was informed that the flex hoses lines from the master cylinder and the abs pump to the rear calipers would all need to be replaced. The vehicle was not repaired. The failure mileage was unknown and the current mileage was 70,000. Kmj.
Slave cylinder on hydraulic clutch failed instantly resulting in loss of stopping ability. Occurred at home in drive without an accident. Could have been catastrophic if traveling on public highway in traffic.
Dealer diagnosis is engine knock hot or cold see history piston moving in cylinder making noise operating to manufactures specs at this time---performed decarb 2 times per gm recommendations noise returns currantly no resolutins per gm for noise. That means that I pay thousands of dollars for a deffective turck, the factory warranty it going to expire when the truck hits the 36000 miles dealer explain to me that when gm find how to fix the problem I can go back and gm going to fix the engine of my truck, I'm sceptical for this comment. Gm built thousands of this kind of engines and I dont think that gm going to expend money and time to fix engines when the wararnty al ready expire.
Brake pedal intermittantly feels as though there is air in the line and needs to be pressed all the way to the floor to stop. Happens regardless of ambiant temperature or engine temp. The local dealer replaced the brake master cylinder at 1515 miles problem still exists. I have talked to other owners who have experienced the same loss of brake pedal feel. I am a little more than concerned that the brakes will fail in an emergency stop.
Master cylinder failed causing the brake pedal to go to the floor. Nlm.
See all problems of the 1998 GMC Sierra.
Brake system: while driving on avenue at 35-40mph, I crossed a railroad crossing while braking and brake pedal appeared to go to the point of least resistance, or near the floor board. Also, while stopped at intersections, noticed brake pedal very slowly moving to the floor while foot on brake pedal. Immediately took truck to the dealer service dept. And the service dept. Diagnosed it as a leaking master cylinder. The master cylinder was replaced however I still notice brake pedal seeking point of least resistance while crossing railroad crossings and dips/moderate bumps in the road. I feel that this is a safety issue due to the fact that I bought this truck as a family truck and it carries my children on a regular basis. I feel that master cylinder should not have leaked at 822 miles. Other issue>>> highway speed vibrations: truck has had a persistent highway speed vibration (40-45 mph and 60-70 mph). The truck was serviced for this problem on sept. 27 and oct. 5. Sept. 27 they balanced the wheels. On oct. 5, they balanced the wheels again and suggested that the wheel weights are "coming off" causing unbalanced tires. Wheel weights have remained intact as of this date but vibration still exist. The vibration feels like it starts at the rear of the truck and migrates through the truck to the steering column and wheel which on occasion has exhibited moderate to heavy shaking including seats and dash. While in turns at times and going over bumps, steering wheel shakes giving the sense of not in control. I feel this is a safety issue since vehicle shakes and vibrates while at highway speeds and something should be done to correct. The gm factory rep. Would like to change the tires to the same brand, goodyear wranglers, however I suggested to him that the truck was in for vibration twice and I suggested swapping tires/wheels to see if this would solve problem and they indicated they did swap but it did not solve problem. This vehicle is not safe.
Initial problem 09/02/98 was both rear axle seals leaking causing brakes to fade. Again on 11/04/98 rear axle seals leaking, adjusted brakes. 11/06/98 brakes locking-up. 11/13/98 brakes grabbing, replaced both rear brake shoes, abs light on-module not activating brake release-replaced anti-lock brake module-master cyl bypassing-replaced master cyl. 01/20/99 abs light comes on-brake peddle hard to push-replaced abs brake valve. 03/23/99 brakes failed to slow vehicle-involved in accident-replaced abs pressure modulating valve.
Brakes were faulty but dealer was not able to find the problem, consumer was involved in a accident due to the defective brakes which caused severe injuries, the consumer replaced the master cylinder and now the vehicle brake properly. Nlm.
See all problems of the 1996 GMC Sierra.
The consumer has been experiencing problems with windshield wiper motor. When turning the windsheild wipers on, the motor makes a lot of noise. The manufacturer has yet to be contacted. Vehicle also has the following problems: engine coolant tank and brake master cylinder are leaking, brakes and fuel pump are noisy, and passenger side defroster does not flow enough air.
Brake master cylinder cover leaks.
On-going / intermittent problem with brake system; brake pedal would be hard to press, causing extended stoping distance. Vehicle been in / out of dealer shop on three occasions and nothing could be found. Can NHTSA help in this matter. Also replaced master cylinder and brake booster.
See all problems of the 1997 GMC Sierra.
When brake pedal was applied it went straight to the floor, resulting in extended stopping distance. Dealer replaced the master cylinder, but that did not solve the problem.
Owner has abs brakes. Brake pedal is very mushy when brakes are applied. Also, problem occurs on all types of pavemenst. Dealer replaced master cylinder which temporay corrected problem. There is also low brake pedal.
Master cylinder stopped working, cause unknown.
While driving brake pedal has to be depressed down to the floor to get the vehicle to stop. Dealer has replaced the anti lock brake control module and the master cylinder, but the problem still exists.
While driving and upon depressing brake pedal to make a normal stop, brakes held for a brief moment and then released, causing extended stopping distance. Also excessive amount of force was applied to the brake pedal in order to stop vehicle. Consumer has contacted dealer. Dealer replaced the master cylinder, but problem still occurs. Please provide any further details.
Upon brake failure, the master cylinder on this vehicle has been repaired or replaced 4 times. The first failure occurred at 86 miles, 2nd at 2,729 miles, 3rd at 43,014 miles, and most recently at 57,270 miles. We are concerned for our safety in this vehicle finding the brake system faulty.
The master cylinder is leaking fluid, resulting in extended stopping distance. The dealer has been notified.
|Problem Category||Number of Problems|
|Brake Electric Antilock problems||
|Brake Hoses, Lines/piping, And Fittings problems||
|Service Brakes problems||
|Brake Disc Rotor problems||
|Brakes Failed problems||
|Brake Fluid Leak problems||
|Abs Brake Fail problems||
|Brake Antilock Wheel Speed Sensor problems||
|Brake Antilock Control Unit/module problems||
|Brake Sensor problems||