EBM_Z06

Hello,

after some fast autobahn driving with a few hard brakes, I noticed a squeal from the right rear wheel/brake every time I drive very slow. Whenever I start from a light it’s a kind of pulsating squeal. As I slowly pick up speed the noise get quicker too, so it’s definitely seems to be wheel/brake related..
I can hear the squeal up to about 15mph, after that I don’t notice it anymore due to increased wind noise.
It sounds almost as if the tire is touching something. The squeal takes place when the car is moving and without the brakes engaged.
Now I came to figure that the pad wear indicators may cause this. What do you guys think ? How do the pad wear indicators work/sound ? About the same as I described?
Has anyone else had this problem? I’ve tried a search but couldn’t find much useful.
Thanks for your help,
Alex

EBM_Z06

anyone ?

Ranger

Here is a thread to read to get you started.

http://forums.corvetteforum.com/show...t=wheel+squeal

Ranger

z06Bigbird

Your brake pads are getting low. The wear indicator is an L-shaped piece of metal at the edge of one of the pads on each wheel. After a certain amount of wear, they will lightly rub against the rotor. This happens when you are not using the brakes.

Time to change pads. You don't have to change them today, unless you are driving a lot daily. Certainly, I would try to change them within the week.

Ed

z06Bigbird

By the way, and some people may disagree with this, you can change the pads yourself PROVIDED that you have a mechanic assist you doing the job.

AGAIN, I WOULD ATTEMPT THE BRAKE JOB UNLESS I HAD A MECHANIC ASSIST ME.

He/she will give you informative hints like:

1. properly lift and SECURE the car. Pucks, places to put jack, use of jack stands, chocks, etc.


2. need to work on one wheel at a time. That way you can compare your work with the original setup on other side.

3. proper box wrenches, sockets, C clamp, special tools??.

4. enough hi quality fresh brake fluid.

5. rags to clean up parts, hands, etc.

6. cleaning fluid to get oil, grease, fingerprints off of rotors and pads.

7. special lubricant for certain parts.

8. additional parts (hoses, sliders, etc).

9. how to properly bleed fluid out of master cylinder, and how to compress caliper without damaging other parts of system.

10. You will need someone to assist you if you need to bleed system.

11. How to bleed oil fluid out without letting air into the system.

12. Wow, this does seem more complicated. (I have done approx 50 brake jobs in 40 years.) Never stopped to put notes down until now.

Good luck. AGAIN. Have a knowledgeable person assist you on first brake job, or first two maybe three brake jobs.

Ed

EBM_Z06

Thanks for all your help so far,

I went to see my mechanic today, unfortunately there was not enough time to put the car on a lift and remove the wheel for some further inspection. From just looking at it from the outside he thinks that the pads are still thick enough. Maybe something like a small rock got stuck in the rotors ?
He’s 99% sure that the problem is somewhere between the pads and the rotors. Has anyone ever heard of the rear rotors getting warped ? So far I only heard of that from the front rotors.
There really is not much noticeable from looking at the outside.
Oh and by the way, when I pulled out of the garage this morning the noise was not there. Once the car gets driven for a few minutes it’s there. It sounds exactly like a warped bicycle rim… I know it might sound silly, but that it definitely the best way to describe it.
I also thought it might be the right axle shaft, but the mechanic said that the noise would sound more clunky and be different than in my case.
Another possibility is that it caused somehow by the parking brake… really don’t have a clue at the moment

BTW, the front rotors have lots of blue spots and small cracks on them and look pretty much shot but are still working great without any noticeable chance. My hope is that it’s only the rotor or pad instead of the axle shaft or something bigger.

lbarnard

I swap my rotors and pads about 4 times a year since I track the car and I don't want to run my street setup (won't work well anyways). If you have not done this before I would recommend getting someone that has. If you can get the parts yourself and have someone else do the job for you this will save some $$. I get rotor's from Rockauto; 4 rotors made in Canada delivered to my house in NC $122.00, yes that is front and rear. Napa is a good source as well buy the Professional Grade (PG) just a side note I buy these for the track, but they are great street rotors. I use Hawk Street pads (not for the track just the street I run race pads for the track). Note the ZO6 maintenance manual says to replace the caliper mounting bolts once you remove the caliper. There are 8 of these. Ecklers sells them or go to Chevrolet they are cheaper they are about $7.00 each; note they sell the washer separate from the caliper bolt, I did not replace these. These bolts get torqued to 125ft lbs. There are clips the pads sit on, you can replace these as well if you need to. I have not. The squeaking or squealing noise could be brake pad wear; unless you have really heated up the rotors I don't think they are warped. For the price just replace all 4. If you are going to flush the brake fluid go ahead and spring for the ATE Super Blue; well worth it and you will be able to tell when the old fluid is gone when the color changes. And one final recommendation, if you have not upgrade to stainless steel brakelines, you should. You will really feel the difference. Good luck.

z06Bigbird

You are right. Rear rotors do not warp as often as fronts. Rear probably rarely warp. Have you ever left your emergency brake on??? Maybe the little drum there is slightly out of round. It could be rubbing against the emer br shoes.

Ed

lbarnard

Good point on that emergency brake as well. I know if you get a lot of heat in the rotors you should never engage that ebrake; bad things happen.

Bill Dearborn

Your description of the sound you hear is just what the wear indicator sounds like. Looking at the pads from the outside with the wheel on will not let you see what the inside pad looks like. The wear indicator is mounted on the inboard pad in the trailing position. On the rear wheels the trailing position is down.

Bill

EBM_Z06

Thanks Bill, I will remove the wheel today... you saved my day if it's just gonna be the wear indicator
Alex