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

 

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

 

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

 

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.

 

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>?

 

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

 

Do Saturns have a separate equilizer? That could be acting up.
Good question.......I'm not sure......

 

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

 

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

 

Okay here's theh latest. They drove it around for a couple of days and

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

Jamie

 

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

 

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