96 S10 Blazer Lack Of Stopping Power

Elishaman · #1 09-17-2004, 06:34 PM

I have a 96 Blazer 4 dr 4wd with 77k mi and it takes almost everything you've got to stop it. I was in a bad accident (not in Blazer) and could not work on the vehicle so my wife took it to the local dealer where they put on new pads and rear shoes as well as a new booster. She said it is a little better but she still does not feel safe in it. They told her all of the 96 and 97 Blazers take a little more braking effort. I think it has air in the ABS unit???? The vehicle is like new and I have always maintained it untill I was injured. Any advise????? I have a friend who is mechanically able to do the work but I have to steer him in the correct direction. HELP!!!!!!!!!

tom3 · #2 09-18-2004, 07:32 PM

Doesn't sound like air in the system. Normally this would cause the pedal to go way down, maybe to the floor. I'd suspect the booster wasn't the correct one or it was installed wrong. Low vacuum or defective booster is the normal cause. Might look at the vacuum line to the booster and make sure you have a good vacuum supply.

BlazerLT · #3 09-19-2004, 10:09 AM

Quote:

Originally Posted by tom3

Doesn't sound like air in the system. Normally this would cause the pedal to go way down, maybe to the floor. I'd suspect the booster wasn't the correct one or it was installed wrong. Low vacuum or defective booster is the normal cause. Might look at the vacuum line to the booster and make sure you have a good vacuum supply.

Spongy brakes usually means there is air in the system.

Elishaman,

Seeing you just had the brake work done, how about you take it for a drive and check it out instead of taking someones word for it.

If something is wrong, take it back to the dealer and have them fix the problem under warrenty. You don't have to worry about this yourself when the problem should be on the dealer's shoulders for this.

Mikado14 · #4 09-19-2004, 12:02 PM

"I have a 96 Blazer 4 dr 4wd with 77k mi and it takes almost everything you've got to stop it."

That statement alone does not imply spongy brakes. It implies a hard pedal, ergo, booster not boosting. Take it from there.

Want to clarify this Elishaman?

BlazerLT · #5 09-19-2004, 12:23 PM

Yea, the blazer does require more force than the everage car to stop.

Face it, it is a 2 ton truck.

Elishaman · #6 09-19-2004, 01:51 PM

I did drive the Blazer and the pedal is not spongy it just takes all the power you have to stop it and it does seem a little low. I took it back to the dealer and they double checked the part number and told me the booster was the correct one. They really did not seem concerned that it was hard to stop. I have read that leaking EGR could be possible cause. The vehicle runs great so I don't suspect it.

Mikado14 · #7 09-19-2004, 05:33 PM

Let's just assume a few things here,

Let's assume that the woman has been driving this vehicle for awhile. Let's assume that at one point, it did not take "almost everything you've got to stop it" for the little lady.

Now, all things being equal after 77k miles, don't you think she would know? If she says it doesn't stop like it used to, and all this work was done, perhaps there is something still wrong.

Could the calipers be bound?
Could there be a vacuum leak?
Could the rotors be glazed over?
Could the booster have been installed improperly? There are adjustments on ones I have installed but never had to do a Blazer, any year. So, I could be wrong on that point.

If the lady says that it is not stopping like it once did, then something needs to be checked.

BlazerLT · #8 09-19-2004, 06:27 PM

Quote:

Originally Posted by Elishaman

I did drive the Blazer and the pedal is not spongy it just takes all the power you have to stop it and it does seem a little low. I took it back to the dealer and they double checked the part number and told me the booster was the correct one. They really did not seem concerned that it was hard to stop. I have read that leaking EGR could be possible cause. The vehicle runs great so I don't suspect it.

EGR does not cause anything to do with the braking so please don't subscribe to that garbage.

Go in there and DEMAND they fix whatever they screwed up instead of just letting them spoon feed you a load of crap and sending you on your way.

Elishaman · #9 09-22-2004, 04:34 PM

The calipers are not binding (all new hardware), the vacuum is about 18.5" at idle, the rotors were resurfaced at the time of pad replacement. According to everthing I have read and in talking to GM techs, there are no adjustments when replacing the booster. Anyone know how to check a booster?

Mikado14 · #10 09-22-2004, 06:27 PM

Elishaman, all new hardware does not imply that the caliper is free from binds. This can be determined by removing the caliper and compressing with the bleeder open. If it compresses relatively easy with a good flow or stream from the bleeder you can assume that there are no binds. Secondly, an inspection of the rubber boot is also required to look for any tears that will allow water, road dirt etc to migrate in.

Here's a question - With the engine running, depress the pedal. Wait a few seconds and shut off engine. Depress the pedal. The first application of the brakes should use the stored vacuum in the booster. The second or possibly the third, the vacuum should be gone and the pedal will be much harder to activate. Is this the case?

Rick Norwood · #11 09-22-2004, 10:03 PM

Sounds to me like the vacuum booster is not boosting. Most vehicles have a one-way valve on the end of the vacuum line where it is connected to the booster. It is held in the booster with a rubber grommet. You probably got a new one with the new booster. Make sure it was installed properly and is not cracked (these plastic valves have been known to crack).

slammed s10 87 · #12 09-22-2004, 10:50 PM

Quote:

Originally Posted by BlazerLT

Yea, the blazer does require more force than the everage car to stop.

Face it, it is a 2 ton truck.

ive got an 87 that will stop faster that any of those riceburners you see 4 words. brembo big brake kit

Elishaman · #13 09-23-2004, 03:09 PM

I have closely inspected the calipers as you noted and I did not see any problems. When I push the piston in there is no binding and good flow of brake fluid from bleeder. After running the vehicle for a few minutes and shutting off the engine the pedal is fine for the first several applications and you can the vacuum booster working, then the pedal gets hard as you would expect when all vacuum is gone. Now here is a new hitch to the problem... I just bled the ABS unit using the valve depresser tools and I got a lot of air out of the unit. I then bled the entire system (rr,lr,rf lf) and also got air out of the system. Do you suppose there had been air in ABS unit all along??????

Mikado14 · #14 09-23-2004, 07:55 PM

Has the stopping ability changed since you bled the ABS?

Is air in the ABS causing the problem you say? Hell's bells, anything is possible. Everytime I think I have an answer, something comes up new and I learn, isn't life grand?

Personnally, I don't see how that would be possible but as I said, isn't life grand?

Maybe we should have asked how far is the pedal travelling instead of assuming that the pedal was normal except for the pressure to apply.

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