98 GMC Ex-cab C1500 ABS Brakes

Guyís I just need an honest answer on this situation.

I presently have a case with General Motors about the stopping ability of the ABS brakes on my 1998 GMC Sierra. This was (as you know) the last of the good small block engines and the combination of disc and drum brakes. I have already experienced one minor accident and have avoided a few others because the brakes do not stop the vehicle in an emergency situation, even worse at slow speeds, 10mph and slower.

What takes place when the brakes are hit hard in an emergency situation the pedal is hard as a rock, ABS module and pump will buzz, the pedal falls slowly to the floor. I mean on the carpet, no pedal left, at the bottom. The vehicle is still moving but slowing to a stop. You cannot get the brakes to even slide the tires. I do know the ABS brakes are good in wet and icy conditions, but hey I live in Dallas/Ft Worth, bad weather is rare here. Our wiper blades dry out before being worn out.

My accident was from a 5 mph application when a lady in front of me started to enter the merge lane then stopped for no reason, actually she dropper her cell phone and stopped to pick it up, I had started to merge with her because the way was clear. I then noticed she had stopped. I hit my brakes very hard, the ABS buzzed, the brake pedal slowly went to the floor, the vehicle still was moving forward and I rolled into her. There was no damage done but I could not stop the vehicle.

I have taken the vehicle back to the selling dealer and two others dealers while the vehicle was in factory warranty over 15 times just for the brakes alone. Each time I have been told there is no problem found, and the brakes operate per factory specs. I took it upon myself to rent the same year Ford and Dodge PUís to see how they reacted when put thru the same situation. The Ford and Dodge both stopped on a dime. Neither reacted like the GMC. Yet I am still experiencing the same problem. My GMC will also lock the front brakes at times when the brakes are applied in an emergency situation. The vehicle has to be backed up for a bit before they will release. I also have had to replace the front brake pads eight (8) times in 38,000 miles. The rears are still factory and still in very good condition. The rotors are still factory but have been turned 5 times due to warping from the excess heat applied when the brakes lock up. They are now in need of replacement.

I am seeking ìHELPî everywhere. If the factory cannot (actually, will not) obligate themselves to a fix the brakes now because of their possible responsibility in my accident, then can you assist. The factory stands on the premise there is not problem. I have searched the Nation Highway Traffic & Safety Administrationís web sight and found many other individuals with the same vehicle as I, and experiencing the same conditions. I watch your show all the time and for years (with my past experience) wished I started the same thing here.

To your knowledge is there a good after market set of reasonably priced rotors, either with drilled or grooved braking surfaces, and pads that will last longer than 4-5k miles? I have asked GM why the new brake pads are so much smaller in surface area than the earlier model PUís. They really could not give me a GOOD answer.

Desperately seeking a good fix. Please advise as best you can.

Thanx,
Chuck DeRouen with a no stopping GMC PU.

well chuck I too am a gm tech and i can honestly tell you that i see many brake concerns , more so on newer vehicles , but i have to say this one is a strange bird. first of all 8 sets of pads?
its obvious that the proportioning between front and rear is questionable , that is very excessive , most trucks that i see are
averaging 25-35k on the origional pads , so it seams your rear
brakes are either not working or you have a severe problem in the front system ,

you stated that at low speeds that the pedal was hard and would
not stop but you say the pads wear fast so i dont think you have
a power assist problem , i would be leaning towards your brake pressure modulator valve. its the part of your abs that controls
the brake fluid flow and pressure which could cause a hard pedal,
lack of braking ability , front pad excessive wear . as far as your abs engaging at 5 mph , it will only engage when a loss of wheel speed is detected and the electronic brake control module activates the pump motor to release pressure to the slipping wheel or wheels. , which would be due to the excessive brake apply at the front wheels , its hard to say for sure but i would steer you in that direction. if all elese fails i would get in touch with the gm gmc regional service rep and try a buyback , if your fed up with the truck , hope to have been some hope

ken johnson

unplug abs fuse the light will stay on but the abs motor will not workit may feel stongy but stops better I have this same thing on a fleet of trucks

what was once known as the "proportioning valve" on pre-ABS vehicles is now called "dump valve", located just beneath master cylinder next to ABS module....although normally very reliable, they can plug and need to be replaced...

[arabian1]

I found this thead and it is the same problem I am having. Disconecting the fuse is not a option because I am selling the truck. Has anyone come up with a better idea?



http://www.twoguysgarage.com/forum/s...earchid=229119

Originally Posted by noworrys

Guyís I just need an honest answer on this situation.

I presently have a case with General Motors about the stopping ability of the ABS brakes on my 1998 GMC Sierra. This was (as you know) the last of the good small block engines and the combination of disc and drum brakes. I have already experienced one minor accident and have avoided a few others because the brakes do not stop the vehicle in an emergency situation, even worse at slow speeds, 10mph and slower.

What takes place when the brakes are hit hard in an emergency situation the pedal is hard as a rock, ABS module and pump will buzz, the pedal falls slowly to the floor. I mean on the carpet, no pedal left, at the bottom. The vehicle is still moving but slowing to a stop. You cannot get the brakes to even slide the tires. I do know the ABS brakes are good in wet and icy conditions, but hey I live in Dallas/Ft Worth, bad weather is rare here. Our wiper blades dry out before being worn out.

My accident was from a 5 mph application when a lady in front of me started to enter the merge lane then stopped for no reason, actually she dropper her cell phone and stopped to pick it up, I had started to merge with her because the way was clear. I then noticed she had stopped. I hit my brakes very hard, the ABS buzzed, the brake pedal slowly went to the floor, the vehicle still was moving forward and I rolled into her. There was no damage done but I could not stop the vehicle.

I have taken the vehicle back to the selling dealer and two others dealers while the vehicle was in factory warranty over 15 times just for the brakes alone. Each time I have been told there is no problem found, and the brakes operate per factory specs. I took it upon myself to rent the same year Ford and Dodge PUís to see how they reacted when put thru the same situation. The Ford and Dodge both stopped on a dime. Neither reacted like the GMC. Yet I am still experiencing the same problem. My GMC will also lock the front brakes at times when the brakes are applied in an emergency situation. The vehicle has to be backed up for a bit before they will release. I also have had to replace the front brake pads eight (8) times in 38,000 miles. The rears are still factory and still in very good condition. The rotors are still factory but have been turned 5 times due to warping from the excess heat applied when the brakes lock up. They are now in need of replacement.

I am seeking ìHELPî everywhere. If the factory cannot (actually, will not) obligate themselves to a fix the brakes now because of their possible responsibility in my accident, then can you assist. The factory stands on the premise there is not problem. I have searched the Nation Highway Traffic & Safety Administrationís web sight and found many other individuals with the same vehicle as I, and experiencing the same conditions. I watch your show all the time and for years (with my past experience) wished I started the same thing here.

To your knowledge is there a good after market set of reasonably priced rotors, either with drilled or grooved braking surfaces, and pads that will last longer than 4-5k miles? I have asked GM why the new brake pads are so much smaller in surface area than the earlier model PUís. They really could not give me a GOOD answer.

Desperately seeking a good fix. Please advise as best you can.

Thanx,
Chuck DeRouen with a no stopping GMC PU.

[carsandcycles]

This thread is six years old, in the wrong section and never was followed up upon. The hot plan would be to create a new thread in the "Your Own Projects" section and re-describe your problem, including all pertinent data, as you know it.

I am closing this thread, as it never provided an answer and is as old as it is. Please try your question again as described above.