Hi,

I have a 91 convertible.

Just had my calipers rebuilt to no avail.
The wierdest thing, when I need to apply the brakes hard, it seems as if the pedal gets stuck half way down, and I cant brake very hard.

If i really push the pedal down hard, it will go past where it gets stuck, but then i hear a strange creaking noise coming from the front calipers.

does this sound like something stuck in the lines?

thanks in advance

 

"Usually", a hard pedal = failed brake booster.

 

If a shop did the work I would get it right back to them for a check. See if they did any work in the MS or booster area.

Did you only have the calibers rebuilt and that was it. Was anything else changed? Don’t know if something could be binding in the calipers during re-assembly, but things don’t move very much when braking applied. Brakes can make a creaking noise if brake applied very hard.

I know they had to bleed the lines and probably did full travel of the brake pedal while bleeding. Maybe something happened with the brake booster or linkage.

 

It almost sounds like there's some corrosion or something 1/2 way down the master cylinder bore that the seal is hanging up on.

This can actually happen since the MC rarely travels down that far therefore it's not getting 'cleaned' by the seal adn can corrode.

Look at where the MC bolts to the booster and see if you see any signs of fluid. If so that could be the problem. If not, it could still be the problem but just not leaking that bad.

Another way to check would be to bleed one of the brakes. When you open the line and push the pedel down there will be no resistance at the calipers. Therefore if you still feel resistance, 1/2 way down I'd be willing to bet it's the MC.

 

There have been reports of ABS units that have issues and cause the brakes to behave poorly.

You might try searching to see if there is anyone who can help you troubleshoot the ABS unit.

IMHO The rough spot in the pedal does sound like a mechanical problem. Like MarkB suggested you should try to cycle the MC without the pressure of the calipers holding it back. In other words isolate each part and confirm its operation to be smooth and free of problems.

 

Thanks for the responses.

I noticed that after really applying the brakes hard, and activating abs, in either a wet road or dry and the pump runs, the brakes are very good.

could something in the abs be hanging up the entire system?

This problem happened before the calipers were rebuilt, so its nothing to do with that.

cheers

 

I've had brake "creaking" noise up front myself a number of years back....had to change the front rotors to get it to quit. The rotors were worn but straight, ungrooved & still above min. spec but creaked no matter what...nothin' wrong with the calipers, pads or pins either. Installed new rotors and all was well.