Well, it seems I've made quite a project out of this one. It started about three weeks ago when I started driving (out of the parking lot here on campus) and began to hear a "squeak, squeak, squeak" sound that got faster the faster I went (the sound is evident under any acceleration, braking, even putting the transmission in neutral and letting it coast). I could hear it from about 1mph to around 60 (where it was so fast that it just sounded like a constant squeak). It sounded to be coming from the left rear wheel, or somewhere around there. I thought it might be the brakes or possibly a U-Joint.

Well, last night I was driving and things started acting very funny. The left rear brake started making a grinding noise and when I came to a stop, smoke started billowing out of the wheel well. I made it back to campus, took off the wheel and I tried moving the brake pad away from the rotor, but it wouldn't budge. I took the caliper off and it looks as though whoever worked on the brakes last put a lot of the "disc brake quiet" stuff between the caliper and the pads, looking as though it caused the caliper to not be able to release from the rotor (I had to have the rear end rebuilt about three months ago, so I'm thinking that's when it was done). I'm not quite sure if it's supposed to be like that, so I'm going to go ahead and put new brake pads and rotors on it (rotors are looking a little warpy, which may also be causing the squeaks?). I also adjusted the parking brake (the drum brake within the hub) so that it takes a little more lever movement to engage the parking brake.

Well, I went ahead to check the other caliper (the right rear) to see if it was in the same condition. I took the pads off and there was no anti-squeak stuff in that one...kind of strange. Well, as I was about to put the new pads in, I pushed in the rear inboard piston and brake fluid started squeezing out of the front inboard piston (between the black gasket that surrounds the piston and the end of the piston). The strange thing is that there was no fluid on the pads or rotor. It seems that when I pushed on that piston, I somehow busted the seal on the other one? Is there anything I could do for it? Maybe just put a new seal on it? If so, how would I go about doing something like that? Would I have to bleed it after putting a new seal on it? I'm not sure if I can get a warranty exchange (it may be too late), so I'd like to able to fix it if possible.

Also, I won't be sure if I've fixed the squeak problem in the left rear wheel until I drive it again, so are the any other problems that could create that sound and smoke? I wouldn't think a U-joint could cause smoke like that?
Thanks for the help!

 

Just replace the whole caliper, those are just prone to problems it's just easier to get a new rebuilt one from autozone for 73 bucks then trying to re-build one.

 

Well, I would very much like to just replace the whole caliper, but I've never bled the brakes before (always having a professional do it and I don't have the money to get someone to do that right now). I'm pretty sure I could do it on my own, having a buddy pump the brakes while I open up the bleeder valve, but I'd really rather avoid having do to that if I could just replace a gasket/seal.

 

It's really not that big a deal to rebuild the calipers yourself. You mention a warranty so you probably already have stainless sleeved calipers. The rebuild kit costs from $15-$25 depending on where you buy them. The important part is to carefully tuck the lip seal into the bore. The black seal that surrounds the piston that you can see now isn't the one that leaks, it's behind that seal. No matter what, you will need to bleed the brakes. The squeaking and smoking caliper sounds like a clogged or colapsed brake hose. You'll find out when you go to bleed if you don't get fluid to that caliper, then you need a new hose. Best to replace them all(4).
Mike

Also, it sound like you accidently popped the piston out of the bore. You may be able to remove the dust seal to get to the piston and tuck the lip seal back into the bore. But I'd replace with new since you'd be that far into the job already.

 

Was the left rear brake damaged enough so that you could tell it was the source of the smoke? (Maybe it was the parking brake or something else).

Was the brake hot when you tried to move the pad away from the rotor? You may have heated the brake fluid up enough that it expanded (or boiled) and this caused the pistons to put pressure on the pads. Clean up the caliper and it should be fine.

The bigger problem is with the leak in the other one. As you found out, the pistons on each side are connected hydraulically. It's normal for one to come out when the other goes in. What's not normal is the leaking of the fluid. There is an inner ring seal on the piston that is not visible since it is inside of the dust seal you can see. The presence of fluid means that the inner seal is leaking - not good if you want brakes! It's just a matter of time before they would lead big-time and leave you with only front brakes.

If you are tight on budget and longer on time, you can rebuild these. I've purchased a rebuild kit that contained all seals and springs etc. and rebuilt them myself. The results were pretty good. If there is severe rust on the insides of the pistons, however, it may not be possible.

Vette brakes are somewhat different from other disk brakes. You should know that there is a spring inside each piston that forces each piston to push on the pad which in turn rides lightly on the rotor at all times. With a buddy to help, it's not too hard to bleed the brakes. (Caution! - women don't have much patience for this type of stuff). If the fronts are still air tight, you may be able to get by with bleeding just the rears. You will be able to tell if you don't get a firm pedal.

Good luck

 

Sometimes the squeaking is from a dry rear wheel bearing.....when it finally gives up the rear disc can interfere with the handbrake shoes which causes billowing smoke....ask me how I know

Before you go too far check for play in the rear wheel bearings.

Good luck.

Joe

 

Thanks for the help so far! Luckily, I just found the receipt for the right rear caliper (the warranty has 15 days left!). So, with this new info, I think I'll take off the caliper and exchange it for a new one. So how should I go about taking the caliper off? If I just unscrew the brake line from the caliper, will fluid go everywhere? I also read the instructions for bleeding the brakes in the haynes manual, so I think I should be ok for reinstalling it and bleeding it.

Also, I've gone through at least 4 master brake cylinders over the past 7 years, with the most recent going out three months ago (When I had the rear end rebuilt and the other caliper replaced). The reason a new caliper was needed was when they were bleeding the system after putting on the new master cylinder, they broke off the bleeder valve, forcing me to buy a new caliper. I'm not really sure why it's gone through so many brake cylinders, but I think the reason this one went out is because I recently had new headers put on and when I drove it from Florida to Arizona (where I'm going to college now), it may have overheated it on that long trip? I'm beginning to wonder if I should just go ahead and replace all the brake lines too as KapsSA suggested?

Also, the pads were pretty warm (but it was about 20 minutes after I got back to campus that I got to it, so they may have cooled off by then). The boiling of the brake fluid wouldn't surprise me on this car...but what could I do to prevent it from happening again? And I couldn't quite tell if it was the source of the smoke....it was really white, thick smoke. It quit smoking about 20 seconds of being stopped...not quite sure what that means. If it was the parking brake, I got that fixed and the new rotors should fix any problems due to warping...

I think for now I'll just get the new caliper, install it, the new rotors and pads, bleed the system and see if any fluid comes out of the rear calipers (to see if the lines are still good). After that I should be able to drive it and tell if that squeak is still there, maybe then having a better idea of what it could be (eliminating most of the suspects). So any tips on taking that caliper off?

Thanks again!

Edit: How would I check that rear bearing?

 

when I had the rear end rebuilt, I think he may have replaced the rear bearing? Here's a list of things done...maybe some of you can make more sense out of it than I can...

This is the type on the bill...
Pinion pre-load shim failed, pinion and carrier bearings ok. Reset pinion preload with new shims, reinstall diff & check pinion to ring side play, adjust as needed. Remove right rear axle, replace bearings and seals.

The parts he has listed as "purchased" are...
2 Rear control arms
2 rubber diff mounts
1 inner axle bearing
1 outer axle bearing
1 inner axle seal
1 outter axle seal
1 pinion seal
1 yoke speed sleve
1 pinion shims

Can you guys make sense of that?

 

Looks like the right bearings were replaced.....that still leaves the left rear bearing as a suspect.

Cheers,
Joe

 

Rotors not running true can cause that squeak you described in your first post. That can also kill your calipers. Check the run-out on the rotor before you replace them.

 

Disconnect the line and cap it off right away with something. (twist tie & plastic baggie drawn tight) You'll loose some....but it won't come gushing out in buckets.

It's fairly new, so taking it off should not be difficult. Clean up the rotor & pads with a solvent like brake cleaner, or something that doesn't leave a residue. I would use anti-sieze compound on the bolts when installing the new one. Be sure to torque those mount bolts to 70lbs ft.
Good Luck
Eddie