disk brake squeak

[bxd20]

I have an odd squeak, with pads and rotors that are only about a year old. I drive highway so the pads are still VERY thick, no cracking, no weird wear, no pulsations in the pedal, rotor is clean.

It's only coming from the driver's front brake.

Here are the symptoms. For the first few stops of the day, no noise. Then once the brakes warm up a bit, I get a squeak only as I barely touch the brake pedal, such that the pads are just grazing the rotor lightly. Push down harder, like a normal stop, noise goes away.

Or it will also happen when I'm going 5mph in a parking lot, and when I turn the steering to the right without touching the brake pedal, I get a squeak. I assume by turning the wheel, I am shifting the caliper just enough to make a little incidental contact happen between pad and rotor.

I tried sanding a bit of the pad off and a bit from the rotors, problem went away for a day and came back. Should I sand 1/8" from the pads, have the rotors turned and re-bed?

These are Morse Ceramic pads with the higher end Raybestos rotors.

 

[Big Jim]

When I wrote this, I made paragraph breaks. When it posted, it ran it all together and didn't respond to editing. Sorry if it is hard to read. Sometimes there is nothing you can do to eliminate a slight brake squeak. You have already taken a reasonable approach. Here are a few more suggestions. You may have a pad that isn't fully releasing from the rotor. If so, you need to make sure that the caliper slide pins are clean and properly lubricated (disc brake caliper grease). The pad backing plate may also be sticking to the caliper. Every place that the pad backing plate makes contact to the caliper should be lubricated with the same disc brake caliper grease. Sometimes you can set up a harmonic from how the pads lead into the rotor. It may help to chamfer the pad along both the leading and trailing edge. You may need a file or grinder. No need to overdue it. A slight angle for about 1/2" to 3/4". Sometimes the noise is actually from the interface between the hub and rotor. If so, some anti-seize at the hub to rotor interface helps. Proper lubrication is one the differences between a good brake job and a great brake job. I always make sure to properly lubricate the caliper slide pins and the pad backing plate and seldom need to do anything else. Actually, I almost always use a little anti-seize between the hub and rotor as well so it is easier to remove the rotor next time. There is still a chance that the noise is from some glaze build up on the pad and/or rotor. If so, you may not have sanded it rough enough to clean it up. When the noise is from glaze, it is usually from a very light brake user or from a very heavy brake user. If you are light brake user, a few hard stops from about 50 mph might be enough to resolve it. Also, keep in mind that it doesn't hurt anything. It is just an annoyance. If nothing else solves the problem, try different pads.

 

[bxd20]

annoying

annoying

Uggg.

First off, thanks Big Jim. Lots of good pointers in that post as always.

The squeak was annoying me, so I broke down the entire brake system at the driver's front wheel. Cleaned everything. Had the rotors turned just enough to get a clean surface. Sanded the pads a few mms. Lubricated with disc brake grease on the slides, and all contact points.

For a few days, it was perfect, no squeaks. Thought I had it licked.

But now the squeak is back, only the characteristics are a bit different.

Now I only get the noise when I'm driving slowly, turning, and off the brake pedal. Like when manuevering around a parking lot. If I'm going straight = no squeak. If I'm applying the brakes, even lightly, while turning or not = no squeak.

But if I'm going slow and turning no brake: "squeak squeak squeak".

Here's the only thing I didn't mention before. Just before this started I had gone to a track day. I used my brakes pretty lightly but still I wonder if I overheated either the pads or the rotors, and they have "changed" materially speaking so they're now prone to squeaking. Didn't have a pulsation at the track or anytime after the track.

Do I throw new pads at it, or try a new rotor. Which is most likely to have "cooked"?

As I'm typing this, I'm thinking of swapping the rotors between pass and driver's sides, and see if the squeak stays on the driver's side or follows the rotor to the passenger side. (Pass side has been trouble free.)

I think that's what I'll do next.... especially since it's quick and free.

 

[hotdimmes]

I have a similar squeak after doing new pads all around and new front rotors. I lubed the slider pins pretty good with brake caliper grease but I didn't do what jim had suggested about the pad backing plate. Something to look into when I install the ss braided lines I suppose. The sound drives me nuts though!

 

[Big Jim]

As I pointed out before, sometimes your only answer is another set of pads of a different composition.

If you are still in the experimenting mood, swap the rotors and champher the pads.