Excessive Brake Pedal Pressure

Gentlemen.... and women,

Here's a question I haven't seen here before.

A faild attempt to make a long story short

My 1996 SL1 was making noise while braking and a slight rumbling sound.

My mechanic, a personal friend, told me that my left front brake wasn't releasing and recommended we replace both front brake units (rotors, cylinders, pads, etc).

He also told me the press in front wheel bearings they put in last year were failing. So they replaced both front units with new units that no longer use press-in bearings.

The car works fine for a few days, but then the brake pedal would become EXTREMELY stiff, with NO travel before the brakes came on. In fact, the brakes weren't releasing at all. I could be in neutral on a hill with the brakes off and the car wouldn't roll. The brakes were definelty locked on. The next time I drove, everything was fine, but a few days later the symptoms returned, so I took it back in.

He told me the master cylinder was bad and replaced it at cost.

A week later, and the same thing happens, only worse. So back to the shop it goes.

What the heck could cause that?

All four brake systems wouldn't go bad simultainiously, right?

Would the power brake pump cause this? That's my prime suspect.

How could a master cylinder cause these symptoms? Did he just replace it because it was the first thing that came to mind? I would think a bad master cylinder would cause LOSS of brake pressure, not excessive pressure.

I've never had rotor warping and the car's been pretty good.

The Saturn dealer in Chicago did try to screw me over way back when the car was new and the brakes squeaked a bit. The Schaumburg dealer service manager told me they get a ton of business from Chicago because of Chicago's attempts to rip people off.

Any insight you might provide would be greatly appreciated. I've searched the web and usenet and can't find another example of this problem.

Thanks,

Timm

Reply to
Timm
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A very common problem with brakes not releasing properly is a defective brake hose. The inside of the flexible brake hose is coming apart and working like a check valve. It lets pressure pass thru, but takes time to release. Usually when this happens, the car will have a tendency to pull momentarily.

James

Reply to
James1549

Thanks very much for the rapid answer! I'll bring it up to my mechanic. However, this is not a momentary issue. It'll do this for quite a while, then be okay the next time I drive it, or it'll "fix itself" after maybe 20 minutes.

When I say the brakes are on, I mean they are ON.

What you say makes sense and we'll definetly look into it. Thanks again very much.

Timm

Reply to
Timm

Timm wrote: > Would the power brake pump cause this? That's my prime suspect.

If the power brake is at fault then the pedal will remain down when it's acting up. With a defective master cylinder the pedal may remain down or return to "home" (or at least be capable of being pulled up with your toe), depending on the nature of the defect.

Reply to
Dan Hicks

What about your back brakes? Seems like you've gone over everything in the front. Maybe you can try pulling up on the ebrake while its acting up(and you're rolling) if it slows you down more, that would lead me to believe its the fronts. If it doesn't really slow you down, look towards the back.

what do you think about that>?

Reply to
BANDIT2941

Do Saturns have a separate equilizer? That could be acting up.

Reply to
Dan Hicks

Good question.......I'm not sure......

Reply to
BANDIT2941

They told me today that they don't have one. I'm assuming that means it's not a seperate part.

Also, they weren't able to duplicate the problem, so my buddy's keeping the car a few days while I enjoy his loaner.

Thanks again everyone! I'll keep you posted.

Timm

Reply to
Timm

Okay here's theh latest. They drove it around for a couple of days and finally re-replaced the front calipers. They're keeping it until tomorrow to see if that did the trick. If so, I'll pick her up and see how it goes.

Wish me luck! Thanks again for the help. I'll keep ya posted.

Timm

Reply to
Timm

Well, hopefully that'll do it! Good luck and do keep us posted!

Jamie

Reply to
BANDIT2941

Okay, Here;s the final (hopefully) update.

It seems to be working! It's been about two weeks and everything is fine. The first day or so the brakes were pretty tight and I was worried that it was happening again. Now they seem to be just fine, short trips, long trips, snowy roads, low speed, high speed.

I'm not sure what the problem actually was, but replacing the front calipers with another brand worked. I'll ask them what brands they used.

Thanks again for all your help and interest!

Timm

Reply to
Timm

It did it again today. I'm really really puzzled.

Reply to
Timm

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