Persistent Brake Squeal

[captainobvious88]

Hi there,

I am having some problems with the brakes squealing on my 2003 Chevrolet Malibu, and I can't seem to figure out why it is happening. The squeal comes and goes, but at times it can get very bad. I've checked over the normal reasons like worn pads/shoes, lubricant, etc. and everything seems to look alright.

The squealing started after I changed the front rotors and pads last July, because I was getting brake pulsations and they were worn out. I originally thought that I did not lubricate the backs of the pads properly, but I had my mechanic look at the front brakes and he told me that they look fine. One thing he did note was that the rotors had a brown tinge to them, which was odd seeing as they have only had a small amount of use so far. We tried lubricating the proper places again to see if that would help, and it didn't.

The next thing we suspected was that it must be a problem with the rear brakes. I took the drums off and inspected them and the shoes, and cleaned all of the dust out. This made the squeal virtually disappear for about 3-4 days, but then it came back the same as before. I had my mechanic look at the rear brakes and, once again, everything looked fine. Actually, the shoes and drums looked much better than they should have been. I have had the car since 2008 and have driven it about 60 000km. I have not changed the shoes or drums at all in this time. He said that the shoes looked almost brand new. He also said that the drums seemed a bit loose, so he adjusted the shoes out slightly to see if that was the problem. This was two days ago and the squeal is still the same as it was before.

We are not sure what could be causing the brakes to squeal, but at this point we are thinking that it could be a problem with the proportioning valve, due to the fact that the front brakes already have a brown tinge and the rear brakes are not very worn at all. One other thing that should be noted is that about 4 or 5 months ago, I noticed that the brakes had started to become very "sensitive." When I would start driving I would press the brake pedal and I would have to press it down further than normal in order to stop, but once it did start to stop, it would do so very quickly, as if I had just slammed on the brakes. After a couple minutes of driving the brakes would return to normal. This only lasted for about a month, and since then the car seems to have been braking normally, for the most part. My mechanic did note that it seemed like too much pressure was being applied to the front brakes when he test drove the car.

Any ideas?

[Tony Silva]

Try coating the entire back side of the front brake pads with a chemical marketed as "DISC BRAKE QUIET". It is sold at most automotive chain stores, Autozone, Pep Boys, O'Rielys...etc etc...it is a pinkish color and comes in a small bottle...probably 6 ounce bottle.

[Moppie]

Originally Posted by captainobvious88

The squealing started after I changed the front rotors and pads last July, because I was getting brake pulsations and they were worn out.

What brand and type of Pad do you put in?

It sounds like you might have got either a very hard pad, or a cheaper low quality pad.

[captainobvious88]

Originally Posted by Moppie

What brand and type of Pad do you put in?

It sounds like you might have got either a very hard pad, or a cheaper low quality pad.

I got "Magnum" brand pads. Here is a link to pretty well, if not, the exact same ones I purchased. http://cgi.ebay.ca/FRONT-Drill-Rotor...#ht_4324wt_905

[danielsatur]

Also see Similar Threads like yours @ the bottom.

[Tony Silva]

The "squealing" you hear is actually caused by the pad vibrating on the disc. The back side of a good quality brake pad will have a shim attatched to it or a strip of kevlar adhered to it. These things prevent the pad from vibrating...which is resonating thru the disc and becomes the squealing that you hear. Cheap pads have nothing on the back of them. try the Disc Brake Quiet stuff. It will cure the prob.

[captainobvious88]

Thanks for the suggestions.

As for applying Disc Brake Quiet, this has been done already, as well as a thorough inspection of the brake pads and rotors, and everything looks like it is fine.

[danielsatur]

Don't be afraid to trigger the ABS, if this car has one.
A little rust on rotors + metallic pads could make noise.

[Moppie]

Originally Posted by captainobvious88

I got "Magnum" brand pads. Here is a link to pretty well, if not, the exact same ones I purchased. http://cgi.ebay.ca/FRONT-Drill-Rotor...#ht_4324wt_905

It's not a brand I've ever heard of, so I did a little digging on google.

It appears your not the only one to have this problem.
Some of the reviews and comments were not good

Reading the description on ebay makes it clear they are a metallic ceramic mix, and "high performance".
This means hard pads, and hard pads are noisy. Cheap hard pads are going to be even noisier.


The next step is to test if it is the pads or not.
If you still have the old pads throw those back in, or your mechanic may still have an old set??

[Tony Silva]

Hey, I drive an AMG Mercedes Benz, but I am NOT one of those rich asshole Mercedes Benz drivers...I do ALL my work my self...work SUPER hard for what my family has ...f everything checks out fine, you may want to try to have the brake disc's shaved...not too much...just enough to take the heat glaze off the surfsce of the disc.1968-1972 chevelles pay my bills and I got EVERYTHING to diagnose and reppaier ANY vehicle up to 2010. If you changed every thing and still have the squeal.....resurface the rotors.

[captainobvious88]

Originally Posted by Moppie

It's not a brand I've ever heard of, so I did a little digging on google.

It appears your not the only one to have this problem.
Some of the reviews and comments were not good

Reading the description on ebay makes it clear they are a metallic ceramic mix, and "high performance".
This means hard pads, and hard pads are noisy. Cheap hard pads are going to be even noisier.


The next step is to test if it is the pads or not.
If you still have the old pads throw those back in, or your mechanic may still have an old set??

Interesting. I might have to give this a try.

[Moppie]

Originally Posted by captainobvious88

Interesting. I might have to give this a try.

Let us know what happens, be interesting to see if it sovles the problem