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Brake problems on a 2005 Pontiac Grand Prix

I recently had my rotors replaced and when I left the garage I noticed I had to press the brake farther than normal. A few days later, I have to press the brake pedal almost all the way to the floor. My brakes sound like there is an air leak when I push the pedal. Sometimes it stutters at the top of the push.

First question is what could it be? The second question is, could this have been caused by the rotor replacement? Seems awefully coincidental.

You probably should have turned right around, and had them check it out. However, now, it sounds like the lines may nee to be bled. Which is weird if they only replaced the rotors.

Also check the brake fluid. This seems like something is wrong with the master cylinder, but if they didn’t touch it, then I’d be very curious as to how this happened, if it did indeed happen at the same time.

Check the thick hose leading to the air assist (the big container behind the brake master cylinder in the engine compartment). It that goes, normally it’s very hard to press the brakes, but it’s really easy to look at. If it’s disconnected, then your engine should be running rough, too, but again, it’s a free, easy look.

Out of time…have to get to work.


Just as a simple check, if you pump the brake pedal up & down & it gets firmer as you pump then the lines probably need to be bled. (That would be car running - without the engine running the pedal will get very firm if you pump it).

If you sit at idle and just apply the brakes firmly does the engine do anything funny? Or does it not notice?

If you just put firm, steady pressure on the brake pedal and it just continues to sink to the floor (even if slowly) the you very well may need a new master cylinder.

If the brake pedal doesn’t continue to sink but also stays soft, then someone should check the adjustment on your rear brakes, and probably replace the flexible brake lines at each wheel.

The rotor replacement could be involved for various reasons. Or it could all be a coincidence.

Hey Again…

Was thinking about this (as you do), and check around your wheels for brake fluid, too. It’s also possible they damaged one of the lines leading to your calipers during the rotor replacement.

Good luck,

Thanks all. I tried pumping the brakes and nothing changes. I do not notice any fluid leaking and my fluid levels are good. The mechanic mentioned something about a “brake power seal”.?. He said it’s rare that something like this happens and he wants to “tear” into it to find out for sure. He wouldn’t charge me for the diagnosis, but will to have it fixed. I guess my main concern is having to pay for something that I feel was caused by having the rotors fixed. Sorry for being a skeptic.

There are two possible seals that could have been damaged:

A seal in one of the brake calipers when the brake pistons were compressed back into the caliper body.

A seal in the master cylinder met its end when the brakes were bled.

The master cylinder seal is the more stealthy of the two failures, as you just lose brake ability, but there is no fluid loss.


It was my brake booster. Thanks all.