Need advice! Metal screeching noises from wheels

[jumpman]

Ok, I've been getting this problem for quite a while already. It wasn't that bad before so I didn't really take note but this time the sound gets worse. I have noises coming from the wheels, ie metal screeching (could be from the brakes or the calipers, I don't know exactly but if im not mistaken both left and right sides have the noise). It is noticeable at low speeds till 40km/h. Above that range and the noise will disappear. I noticed that it normally occurs after the car gets warmed up. Could it be the heat causing the metal to expand? Cos I was told that the air duct at the bumpers channel air into the braking system to help cool it and prevent overheating. Could this be the case?Hope I can get some advice from you all, thanks!!

 

[Jerman]

bro,
Check your brakes or the calipers first. If not, it could be your wheel bearing.

 

[jumpman]

thanks for your input bro Jerman. So far I've got the brakes and calipers checked...so far nothing out of the ordinary. Wheel bearing I have yet to look it up with the mechanic.

 

[pussy]

check your brake dust shield, it might be touching your discs.. hot it expands, then they will touch the discs..

or

check your front wheel bearing...

 

[jumpman]

Thanks bro pussy. Will look it up!

 

[jumpman]

Ok, I have gone thru the matter with my mechanic. He mentioned that it might be dirt stuck on the surface of the disc/caliper and adviced me to spray water to wash it off when the brakes are cool.He did not tink that those items that we had discussed about here is the problem.So, I tried his way of doing it but the sound(as in when the car is moving without applying brakes) is still there. Moveover when i brake harder when the car is slowing (roughly at about 40km/h and lower) the screeching sound is unbearable..

Also does this have to do with the cooling ducts that channels air to the brakes ? I had taken them off when I applied my Mtech bumpers. Another thing was that when the car is cool..the pedal travel to apply the brakes is more compared to when the car is warm or during a hot day.

Thanks all bros and sifus!

 

[naharnms]

Bro.. dont forget about the hand brake spring (if the sound comes from the rear), probably stuck there and cannot release properly due to rust..
my 2 cents..

 

[camber73]

I think it might just be the brake pads are worn out. Screeching when not applying the brakes would indicate the caliper is not releasing properly. Screeching when u do brake, would usually indicate the pads are down to the squealers. Pads may not have worn down evenly. Might just want to pull them out to check.

Here's something i pulled off the web that may help :
Brake squeal: This is a high pitched squealing noise, often heard when you are going slow and are not applying the brakes. If it goes away as you apply the brakes, it could be coming from the brake wear sensors. (Also called 'squealers' by mechanics.) They are small bits of spring steel that are attached to the brake pads in such a way that when the pads are about 75% worn out, the sensors start to rub on the rotors, making the noise. GM invented them, and they are one of the best ideas anyone has ever had in the automotive industry. The sound is so scary that you usually go to a mechanic before any major damage is done to your rotors, and before your braking power is compromised, saving you money and maybe your life.

 

[virtualmystic]

I had the same problem and traced it to the rear right brakes on my 325 E30. The problem was that the brake caliper floating mechanism was jammed and thus the brake shoes did not "float". This led to one of the pads (of the pair) not withdrawing completely from the disc and wore it off until the fasteners (normally rivets) that held the brake shoe to it's backing plate was exposed. The rivets made a deep groove in my disc which had to be replaced. I ended up replacing both rear discs and of course the brake shoes. have a good look at both the inboard and outboard brake pads and see if they are wearing down evenly. Otherwise you'll have to pull them out for a closer inspection. You can watch the video of my squealing brakes here.

http://www.youtube.com/watch?v=Mgp2SjkfIuo

 

[virtualmystic]

Hello Jumpman, did you solve the brake screeching problem on your car? Great if you can feedback and we can all learn a thing or two.

 

[jumpman]

Hi guys, I'm really sorry for ignoring this thread. ok, from further investigation it was found out that the caliper pistons are indeed not releasing properly making it jam. This was on my left front caliper. I am on rear drum brakes so the sound/problem definitely came from the front. I consulted another mechanic and he suggested to do some skimming or cleaning on the pistons but i've not gone thru that yet..currently no time as well as waitin for the new engine to arrive. so until then..that's all i have to share.cheers!