So about a month ago I started getting this squeeling noise from the front left of the car. I didn't have the money to fix it right then, but I knew something was up so I just checked her over and things seemed fine except for the squeeling. Break pads look brand new and there is nothing major going on with the cv boot, cv joint, steering arm or otherwise. Just the normal wear and tear of a 66,000 mile mini. I decided to get new break pads anyway, just to see. After pulling off the old ones and inspecting them, there was no sign that it was the pads. So I put the pads and caliper back on and determined that it may be the rotor. I started turning the rotor and noticed that it was a little tight in one spot. I stared directly over the rotor and the caliper and determined a distance between the 2. As I was turning it, the gap got slightly smaller in the area that it was tighter.

Does this sound like a warped rotor? Maybe it needs to be resurfaced or replaced. I need some advice before I spend the money on new rotors. Also I have a trip this weekend and it's about a 3 hour drive. At highway speeds with the rotor rubbing like that, could it heat up enough to catch fire? They are ceramic pads so I wouldn't think so, but I figured I would ask.

 

There will often be some runout on rotors. Warping is usually identified by a shimmy in the steering wheel when braking at speed. I wouldn't worry about a fire, but if the runout is enough to push the pad away from the rotor, your initial brake bit might take longer. Can we assume the squealing stopped? Sometimes a rock will get wedged against the backing plate and cause squealing.

 

Yup. BTW, you'll feel the shimmy in the steering wheel if the front rotors are warped, and you'll feel it in the chassis/brake pedal if the rears are warped. There's no fire hazard.

 

I can definitely feel a little shimmy in the steering wheel while driving and especially when braking. I checked for anything that may have gotten stuck in there but everything seems ok. The squeeling is still there too. Maybe it is just a warped rotor then?

 

What I would describe as a symptom of warped rotors would be a pulsing in the brake peddle. Get going about 60 & lightly hit the brakes & you will feel it in the brake peddle. At least that has been my experience on a few cars.

As far as the squeaking goes that is an odd one.

 

If the brake pads are good, and it's still squealing, I'd make sure the backing plate isn't bent and hitting the rotor. Sounds like time for new rotors.

 

Or maybe it's a bad front wheel bearing?

A warped rotor generally won't cause a squeal, the nature of it is to be uneven so it would not make a continuous sound.

I had a squeal in the front of my wife's Audi right after I did some work on it, turned out just like Eric said, I'd bent the backing plate a tiny bit and it was just barely touching the rotor. A quick bend back and all was fine....

 

Is the squeal all the time or only when you apply the brakes?

If all the time, it is probably something like the backing plate hitting the rotor or debris wedged between the plate and rotor. Since you had the brakes apart, it is probably not debris but instead that the backing plate just needs to be bent away a little.

A warped rotor usually does not cause a squeal. Usually the pads cause a squeal. If you only get the squeal when braking you might try some hard stops to clean off the pads/rotors. Some pads just squeak no matter what you do and you might just need to replace the pads. You can also try the various anti-squeak products made for brakes. They are usually a compound or material that you apply to pad plate.

 

I appreciate all the replies everyone. The squealing is continuous all the time, except when I apply the brakes. It's odd but as I apply the brakes to slow down at ANY speed, the squealing stops. If I lightly apply the brakes and stay on the gas, there is no squealing. I know that I'm just killing the pads when I do that, but I thought it was odd. I also bent the plate behind the rotor away from it as much as I could, all the way around and checked for any rocks or other debri and there was nothing. I'm thinking it may be the wheel bearing but applying the brakes wouldn't stop the squealing from a wheel bearing. I'm lost.

 

Here's a test that may help you isolate the noise to either the front or rear. While driving pull up the e-brake a bit & see if the squealing stops. If it does, then it's the rears. If that turns out to be the case check the inner brake pads & make sure the spring clips on the inboard pads are intact & attached to the caliper pistons.

 

I have isolated which rotor it is already. It's the front drivers side that is the problem. Braking does stop the squealing, so I'm not sure what it is

 

Pull the pads & have a look at them. Could be as simple as a stone stuck in there. You need to find the cause & cure it. Good luck.

 

Thanks for keeping up with my thread man. I'll pull all the tires and pads this weekend and see if I can't figure things out. I'll repost when I figure out what the heck is going on. If nothing else, atleast this will be a thread for some to refer to in the event that they have the same issue.

 

Ok, I finally got a chance to get back here. You will never believe what I found... I put the car up on all four sides and started with the back driver side brakes. That's where I found my problem. I'm not sure how it happened or what sense I can make of it but the rotor bolt somehow worked it's way out and the rotor was shifted a bit forward, which is the confusing part because the lugs should have been holding the rotor in place. The caliper shifted to the rear of the car somehow, and the brakes were actually compressing onto the outside of the rotors rim and not on the face. That's what was causing the squealing. Needless to say, there was some very odd pad wear and the rim of the rotor was almost flush with the face. I pulled the pads, and decided to just even and resurface them because there was still a lot of wear left on them. I threw them back on and tightened everything down. There is no more squealing and everything seems to be working fine now. Any thoughts on this?

 

Glad you found the problem.
I agree that the rotor should not really have been shifted because the lugs hold it in place not the rotor bolt. I suspect it was more that the caliper shifted slightly. Hopefully you removed and reinstalled the caliper bracket and torqued the bolts.

 

I find that one hard to understand. If the wheel was bolted on no way the rotor could move out of position. I bet it moved once you removed the wheel that was holding it down. As quik said I'm make real sure the caliper bracket is on correctly & torqued down. IIRC it is something like 81 ft lb for those bolts.

Glad you found the problem.

 

Thanks again for your responses. I'm sure that the caliper is on correctly and alligned now. I made sure of it that day and the squealing hasn't returned. You're probably right about the rotor and when it shifted, it just seemed odd to me.