87Formula4bbl

I have now had two different disc brake rear ends, and both seem to have the same problem. Something is rattling pretty bad on the bumps, and I know that its not the bearings. I have checked all bolts on the LCA's, Torque Arm, Panhard Rod, everything, everything is tight, no movement at all. Gas tank is tightly secured, heat shield is tight, exhaust is perfectly suspended, etc. I even just now replaced the shocks, even though I know now that the old ones were good, because it still does it. I am almost positive that it is the brakes, you can hear it more on the drivers side than the passenger side. Just driving in a rocky driveway at 3-4mph it is audible.
Are disc brakes known to do this? Do they need rebuilt? If so, what is involved in a rebuild, is it an amatuer-do-it-yourself-er job? If not this, does anyone else have this problem?
Any comments or help is appreciated, as it is very annoying while driving everyday in this pot-hole wasted roads town.

yankeecarman

iTrader: (9)

You will probably hear from more qualified people than myself and mine does it too. I understand there is a shim kit for the rotors that will fix the problem. It is very annoying.

87Formula4bbl

Well, I know now, at least, that mine arent the only ones that do this right?

Now, I just need to know what to do to fix it!

I havent heard of the shim kit before, where do you get this from, any specific place or does Jegs or Summit carry them?

yankeecarman

iTrader: (9)

Probably talking to the wrong person because I live in Australia. I know that you will be able to get the parts from one of those places and I expect your local parts supplier would even have them. My friend tried putting some strong glue on the backside of them somehow and it worked for awhile, but now back to the noise. That at least tells me that the shims would help. I think the glue was some sort of filler to act like the shims would. Let me know I am interested.

87Formula4bbl

That seems odd that they would need shimmed like that, especially considering my rear that I have in now is from a newer camaro (4th Gen.). I would think that GM would have had that problem fixed by now or whatever year the rear is. Weird. I was thinking it may be in the actual ..... Caliper bolts, I think they are called? I was thinking they may be worn out, but I have not had the time to thoroughly check them out yet, maybe this weekend. I'll let you know what I find out.

Just stay tuned to this thread, hopefully some more knowledgable people come in here and can help me out.

I know this is the saddest thing in the world almost, but these things rattle so much up on these roads that it almost makes me too embarassed to drive it......And it would really take a LOT to make me not actually WANT to drive my car, just ask my girlfriend! LOL

ANDYZ28

Please post a picture of your brake set up, and I will try to help you.

Thanx,ANDYZ28

Benny

Does the noise stop when you tap the brakes? I know the rotor is only held on by the caliber and wheel. Mine does the same thing routinely.

87Formula4bbl

These are the best pics I have for now, until this Saturday....

87Formula4bbl

Sorry they are so small, they are high quality pics and the server won't let me upload much bigger file size than this.....

87Formula4bbl

Here's one more...... I hope this helps a little....?

87Formula4bbl

Benny: I cannot tell with this one if it will stop when I'm on the brakes or not because currently they are not working. I am not quite sure, but I think I need to replace the master cylinder. I'm not getting much pressure to the rear brakes. Anyone know anything about this too? I was reading in another post that it may be the MC but I haven't had time to tear it apart and check it out yet. But yes, what little pressure there is, Benny, it seems like if I get on the brakes hard on a bumpy part of the road, the noise seems to lessen a little bit.

I've checked to see if the wheel is loose any, by pulling, pushing, lifting on the wheel, to see if the bearings or anything are loose, but no. That is what leads me to beleive that the actual disc itself is not moving around inside the brake assembly, but that the brake assembly itself is rattling on or against the rotor maybe.

yankeecarman

iTrader: (9)

The heavy glue that I mentioned was more or less a filler behind it to use as a spacer. I am sure this would be there to act as a shim. Wouldnt need much of one to stop the noise. One of those things that is too easy to put off doing until another time. But I do want to get it fixed. Also mine is on the front end not the rear.

BretD 88GTA

I suspect your problem is much simpler. Slide the driver's side caliper off the rotor and check to see how tight the pads fit. It sounds like the pads are loose in the caliper.

It appears you have upgraded to the '89+ rear discs. Since my car has the pre '89 cast iron discs, I'm not sure how the pads are held in on your car. IIRC they use guide pins? On my car, there are tabs located on the pads that can be bent to ensure a snug fit. Some CRC anti-squeal adhesive could possibly help you as well.

biff85ta

Is the e-brake in the caliper if it is you probably just need to set it a few times as gm rear calipers with an e-brake have a ratchet mechanism in the piston and you must use the e-brake in order for it to adjust this was the case with my fiero`s and my current 91 gp as well as my parents 90 lumina all of which used gm rear disc brakes

87Formula4bbl

BretD: Yes, the whole rear is from an '97+ Camaro or bird, not sure exactly, so it is definitely the new style brakes. The pads have a little 'spring' sort of thing on 'top' that hold it snug in the caliper, so the pads themselves are not rattling im almost positive.

Now that Biff mentioned it, I wasn't aware that the brakes had to be set using the e-brake. My e-brake cables are not hooked up because they were not long enough to reach to the main cable. I just totally unhooked them. If perhaps they DO need adjusted, do I just tug on the lever to actuate the e-brake (mounted below the caliper)? Will this tighten them up, so that if the pads WERE too loose and that was the cause of the rattling, that they would be more snug against the disc?

This is all hypothetical, but I think I might be on to something here. I will definitely take a look at it tomorrow when my girlfriend brings up a jack and a jackstand (I hate living in an apartment at college 2 hours from home!).

Thanks a lot guys.

87Formula4bbl

I was also thinking that, since all the noise seems to be coming completely from the driver's side, maybe this side needs adjusted more-so, that is what makes it rattle so much, maybe it is way un-adjusted compared to the other side?

biff85ta

just work the e-brake arm back and forth until they tighten up but make sure you leave them in the off position when you get done hope that it solves your problem if no it was surely worth a try.

87Formula4bbl

Oh, it's DEFINITELY worth a try! Trust me....

I dont think the e-brake lever should stick in the 'on' position, I left the heavy spring in there...

Thanks for all the help, if this don't work, I guess I'll be back in here again....I'll figure it out some time or another.

ANDYZ28

I believe the E brake adjusting the calipers was for the early Delco-Moraine iron calipers. The later PBR aluminum calipers work differently.

Thanx,ANDYZ28

87Formula4bbl

OK, so I pulled off my wheel today to take a look at the brakes. I didn't spend too much time looking at them b/c its like 30* out. I tried to adjust it using the e-brake, but I don't think that it did much good. It didnt seem to tighten them any. So I think that ANDY was right about that. Any other ideas? Should I try shimming the rotors? This is so aggravating. ARGGGHHHH.

87Formula4bbl

Anyone??

BretD 88GTA

Since you swapped in an entire 4th gen rear end, the rotors shouldn't need any shimming. This problem is a little tough to diagnose online.

Here's an idea. Have you tried one of the 4th gen boards? Say LS1.com or similar. Talk to some of the 4th gen guys and see if this problem has come up before. They may be able to help you.

87Formula4bbl

Well, I took off the wheel and then the brake caliper today to take a look at it since it was actually nice outside. I'm starting to realize something here.....

The disc is hardly even shiny, it looks like the pad is just barely rubbing against the disc, and I took the pads off and looked at them.....THEY ARE STILL SEMI-ROUGH!!

This means only one thing....my rear brakes are not working either properly, or not at all!

I took off the cover to the reservoir on the brake booster and depressed the pedal to the floor slowly many times, with the rear brake caliper still off the disc, to see if it was working at all. Well, after about5 or 6 complete pumps of the pedal, the master cylinder in the brake finally extended outwards about half of the way. Also, I noticed that while I had the reservoir cover off and pressing the brake pedal, little bubbles were coming to the surface in the front half of the reservoir (front brake portion?) and in the back reservoir (rear brake portion?) it would shoot a little stream of brake fluid up into the air about 3 inches or so, depending on how quickly the pedal was pressed.

OK, now I wouldn't think that this should be normal. Does anyone know if this may be the problem as to why constant pressure is not being held in the brake lines (i.e., retracting the brake master cylinder back into the housing, instead of keeping it held flush with the rotor until the pedal is pressed?) It sounds to me like I need to rebuild the the master cylinder in the brake booster, or at least replace it...

Any suggestions?

Sorry if I'm exhausting this subject, but I feel I've found some new relevant information which someone may know something about.

camaro_1983_383

i dont know if this will help or not, but i read an article in Hot Rod probably a year ago where they made a plate to go over the M.C. with a air hose fitting and bled the brakes really well, better than any product theyve ever tried. if you want, i can give you instructions, but then again, i dont know if this is your problem. Also, was it very hard swapping in that rear? i might like to try that. how much did it cost?

AFreaknGoodTme

Follow the lines, the front half of the master cylinder reservoir (small side) feeds the rear brakes. Fluid will shoot out of both front and rear parts of the reservoir similtaniously if the system is bleed and adjusted properly.

Sounds to me that you have air trapped in the rear lines. I would recommend having them professionally bleed if you are not familiar with the proper process.

87Formula4bbl

camaro: I don't know that it is a problem of bleeding the brakes, I have bled them numberous times, just to make sure.

Concerning the rear end...it was easy swapping it in. It's a direct bolt-in.

Cost me $150 from the junkyard, but then again, I think I got a good deal on it. I think they usually go for $200 - $500, depending on what you want/get.

biff85ta

If you decide to bleed the brakes again a method that has never failed me is to put a small hose on the brake bleeder and run it into a plastic cup with brake fluid in it and to pump the brake pedal several times with the bleeder screw open. I have one question for you did you remove the factory residual valve or was your car a disc brake car orginally

87Formula4bbl

By residual valve, do you mean proportioning valve? I am not sure of the technical terms here, but the valve below the brake booster where all lines run into/out of?

I replaced this a while ago with one from an '84 Z28 Disc Brakes, so I would imagine that it is set up for disc brakes, though it may not be.

davecamaro

Man ive been on the hunt to find this problem for years now
and nobody knows what the ****ing thing is..
I changed everything front end wise.. rotors.. brakes etc..
nothing gets rid of the problem.
good luck!

87Formula4bbl

The way I see it is this:

When cars get older, it is understandable that rattles and what not can form here and there, and can be hard to find.

But as far as I know, a newer camaro isn't going to form such a bad rattle so early in it's life. And this rear is from a newer camaro. So what gives?

It must be something that is worn or something in my car that is causing the looseness in the new rear, like the master cylinder or something. Maybe they DO need bled really bad again like freakingoodtime mentioned.

I'm gonna try this and see if it helps.

I know for a fact that the rattling is caused by the brake pads being loose and rattling against the disc now, I just need to find out why they are loose.

85IrocNOH

I just got done redoing my back brakes completely About 2 weeks ago due to a similar problem. on the side of the caliper with the piston, there was a pretty sizable gap between the rotor and the brake pad on the driver and pass side of my 85 iroc. My back brakes did not work at all. I thought it was the calipers originally so i went out and bought new calipers, brake pads, and e-brake cables. It turned out to be a bad master cylinder. I got one off an 87 GTA for 20 bux at a local junk yard w/ the prop valve. I only changed the master cylinder up front tho. Is your brake pedal spongy with alot of play in it? Mine would go about 2/3 of the way to the floor before the brakes would work at all and then it was only the front ones. here's my post with pics of the gap between my brake pads and the rotor. https://www.thirdgen.org/techbb2/sho...hreadid=140636 I don't know, just my .02¢

AFreaknGoodTme

He does not have the same calipers as you do. Iron calipers on the earlier cars are prone for this because of and entirely different reason- The parking brake assembly stops adjusting properly over time. PBR calipers do not have this problem.

87Formula4bbl

My brake pedal is somewhat spongy-feeling, but I think it may be due to air in the lines now. My dad talked to a mechanic on his route (he's a UPS driver), and he said there may be a leak somewhere in the line, posibly the MC or the Prop. Valve. I checked underneat the Prop. valve today and there is some sort of nut or bolt underneat I think. Well it was moist with brake fluid, but it was apparently not dripping, at least not that I could see. The area underneath was pretty clean and I didn't see any signs of leaking, but it may be just a small enough hole so that air gets inside, and it IS on the 'front' side, which would go to the rear lines. I'll check it out some more tomorrow.

biff85ta

on drum brake vehicle there is a valve either in the master cylinder or on the wheel cylinders themselves that holds pressure to keep the drums working properly but after I thought about it for a while if you still had one your rear brakes probably would have locked up by now