PontiacBonnevilleClub.com

'01 Grand Prix GTP Coupe...55K miles

After sitting overnight (or when putting in reverse anytime), I feel something in the front of the car (through the steering wheel) "release." It's very subtle but that's the best way I can describe it. My best guess is a hanging brake caliper. Caliper pins sticking perhaps? I believe these are the original rotors and pads. I jacked the car up and the tie-rod ends are tight.

Your thoughts?

Brakes would be a good guess. I am assuming this happens when the car is started. You say you feel it? Through the wheel or through other contact areas?

If it's not through the wheel then it may be a trans issue. Trans or drive axles. The the only other suggestion I can make is that you may need to check your steering gear for secure attachment or bends.

I am just guessing here, but I hope you figure it out. Tooling along at 70 wondering if your car's going to come apart kinda dampens the fun of the commute.

Through the wheel but very, very subtle. I feel something "release" once and then that's it--I don't feel anything else during my trip. Drives straight and true and shifts well.

Has your intermediate steering shaft been replace/fixed? Maybe strut mounting plates? My mounting plates are going out in mine.

Come to think of it I had a similar problem a year ago. I'd take off down the road and about 100ft later I'd hear a little sliding thunk. Turned out be a hanging caliper like you said. I rebuilt the calipers on each side. Was only about $20 per side. Could be yours is sticking too and just powering the brake system puts it into place. If you're mechanically inclined and you have some experience you could try doing it yourself. Chilton manuals are like $20 too. Read that before you do it. With brakes safety is the first priority. So if you do do it do it right.

one possibility to find out if that's it is to put your foot on the brake before doing anything else and hold it to see if that alters you 'release' feeling.


Kris

I've done brakes several times on my past vehicles but have never had to rebuild the calipers. What is involved?

Intermediate shaft is a good guess but this is a different feel than that. Definitely coming from the front wheels. You can "sense" it.

Kits and cars differ, but, basically you clean all the parts and replace the seals and dust boots. The caliper piston can become scored or nicked. You want to take some very fine sand paper and polish the piston all around to keep it hanging up. You can see where that may be you're problem. This is great time to paint your calipers too. They sell kits but thoise are pretty expensive and unnecessarily so. High temp engine paint work great for that.

The procedure is fairly short and simple. Get a chilton or try Autozone.com for the procedure. You'd be looking at 2-4 hrs at the max.

More likely than something being wrong with the caliper (not that I'm saying the pins should not be relubed every so often), your brake hose might be collapsing on one of its inner layers and causing a slow fluid drawback. Also, new reman calipers usually run about $20, much easier than rebuilding your current ones if you feel they need to be replaced.

My MIL just got a 2002 Regal (first W-body I've worked on). It had the exact same feel you are mentioning, and I thought it was a CV joint.

Did the front brakes, and found that they were in BAD BAD need of bleeding (calipers full of air). After new rotors and pads bleeding and bedding, the issue was completely gone.

I think the caliper pistons were "receding," allowing the pads to loosen up and/or wobble around.

I found a complete illustrated guide to changing W-body brakes, as well as torque specs scanned straight out of the FSM, on grandprixforums.net (or was it clubgp?). It was easy, much easier than an H-body (pre-2000, anyway) IMO.

Sounds good. Will the Grand Prix brake job (pads/rotors) look about the same as my '00 Bonneville once I dig in or am I in for any surpises? The rotors are original from '01 and looking a bit thin so I think I'll go ahead and replace. I doubt they can be machined.

Thanks.

I have not yet tackled brakes on my 2004 LeSabre, so I cannot comment on similarities or differences between W-body and 2000+ H-body brake job.

the job is very similiar

Finally dug into my front brakes with new pads and rotors and quickly found the culprit--upon removing the caliper from the rotors, the inner pads completely fell away from their metal backing plate. I'm assuming this was allowing them to slide back and forth quite a bit. I'm guessing these were the original pads and rotors from '01 with only 55K miles on it. Had the original tires as well. (which have been replaced). Primed and painted the new rotors with high-heat silver so they won't rust.

You painted the rotor surface? That's a no-no.

There should be nothing on the surface of the rotors or you could have braking issues. But between the heat of the pads and the friction, i'll bet that paint it gone after the first few stops.

Rotor's get rust on them, that's just how it goes. Just drive it daily and it won't be a problem.

Can't imagine anybody being silly enough to paint the actual braking surface.

Have a nice weekend.

harrydunn wrote:Wow, I really cannot imagine anybody being silly enough to paint the actual rotor surface that comes into contact with the brake pad.

You would be suprised... lol

A friend of mine did that on his cavalier. The pads burned through it pretty quick but still

Ha. Yep, I would think it would burn off pretty quickly. Probably didn't smell to good though!

Ha ok. I didn't think so... but the wording made it sound like you painted the rotors completely and I just went... well anyways. Good to hear it's fixed up! Beautiful car BTW.