No Brakes

I own a 1997 Grande Prix. Occassionally I have no breaks. It makes a like crunching sound when I press on the brake pedal and I have no brakes. I press a few times and they would come back but not all the time. I have had the master cylinder replaced and they bled the brakes, but it is still happening. Has anybody had this problem before? I need help because it is scary not knowing if you are going to stop or not!

Well first of all, stop driving that car.

Second, does your car have ABS?

Is there any resistance in the pedal, or does it travel to the floor?

The rear brakes might be worn down to the metal and the rubber cups may be hanging out into space. Rear drum brakes only. The master cylinder may have a shared reservoir. When you start off, the fluid from the front goes over the hump and ends up in the rear end, then you pump up the air and the car finally stops and some of the fluid comes back to the front and it seems like you have working brakes. That’s just one scenario that has happened before. I don’t know why brake reservoirs are made that way. It isn’t safe.

Pump up the air? There shouldn’t be any air in 97 Grand Prix brake system. Modern master cylinders always isolate brakes, either front and back or diagonally split, there is no fluid going over humps.

need more info.

when the MC was replaced, was a brake job done then too? just front, or front and rear? you mention ‘crunching’ do you mean in the brake pedal, or is it coming from the brakes themselves?

what type of mechanic did these repairs? hubby? neighbor? local mechanic? discount chain? national chain?

do you have the receipt from the previous work? what exactly is on the whole list of stuff done?

when you took the car in, was it specifically for this ‘crunching’ sound and no brakes, or did this problem pop up after you took it in for work?

Agree with others who say you can’t take this car on the road in this condition. It sounds like the new master cylinder is a dud, defective. Whoever replaced it should redo the job with a new one under warranty. If the new cylinder was done several months ago you maybe out of luck on the warranty.

In that case go to a brake specialty repair shop and get it fixed properly. Rent a car if you need to in the meantime. An accident will cost a lot more than a rental and if your insurance and other parties find out you were driving with known defective brakes you could be in serious ----.

This may be a WAG. Have someone observe the brake pedal mount while you step on the pedal. I am thinking that the pedal arm pivot is moving because something is wrong with the structure it is mounted to or the pedal arm itself.

No matter what, don’t drive this car until the problem is fixed.

I did stop driving the car until I got it fixed. But I am not sure if the problem is totally fixed now. The car does have ABS and the pedal does travel to the floor making a crunching noise.

Thanks for your input.

So then if there is no air then they didn’t need to bleed the brakes?

Thank you for your input.

Thank you for your reply…I thought the problem was fixed when I had the MC replaced by a licensed mechanic. After it was replaced I drove to Edmonton and by the time I got there it happened again. Since I have been back he bled the brakes again and I felt it happen again…but the brakes came back. I just want to be positive that I have working brakes. Thank you for your input.

Do you think the crunching sound is flexing of the components affected by the pedal pressure? When I first started reading I was thinking of a rust condition on the rotors and pads,no gripping power.

Hey thanks for your input and I have no idea but I am seeing the mechanic again and will relate what you said. I know I just had the pads replaced and nothing was said about the rotors then.