[Davis137]

Good Morning All,

I've had this problem with my Escape ever since I got it. Originally, only the front RHS was making a chirping sound while driving, but now the LHS front is doing it too, and it makes my truck sound/seem like a hunk of junk. The chirping sound only happens while I'm driving forward above 10kms/hr, and it goes away the instant I apply the brakes, and comes back almost instantly after letting off the brake pedal. I'm also getting a steering wheel wobble/shim when I slow the truck down at highway speeds too...

I've been told by my dealership that if the truck sat a lot before I owned it, it's possible that there is a corrosion ridge on the outside edge of the rotors, which have worn the brake pads unevenly/out of shape, so now the pads have a slight bit of travel/play in them, and rub on the corroded edge of the rotors, causing that chirping sound. They said it's also possible that the pads or the rotors being worn unevenly might cause the steering vibration under braking too....

Any thoughts?

 

[Surfscape]

Vibration when applying the brake is usually a warped brake rotor. The chirping noise when the brake is NOT applied seems odd. The brake pads should be making contact with anything unless they are not properly mounted in the caliper.

The only way to cure the vibration during stop is to have the rotors ground flat again (which few places do these days) or replace them (much cheaper than it used to be and many choices).

Auto stores sell a brake lube spray that can be sprayed onto the back of the pads that can stop potential squeak causes without tearing the brakes apart, but if you want to get rid of the warp the all thens other issue will get addressed too.

Other possibility... Wheel bearings or CV joints. If dry they can cause the noises which would change once under the load of applying the brakes, and can cause vibrations in the wheel.

 

[Squishy]

Actually, the pads should normally be contacting the rotor. If you were to completely lift the pads off, you would end up with a very low brake pedal.

But all the suggestions are good ones. Wheel bearings can be checked with the suspect wheel off the ground, and grabbing the top and bottom of the wheel. If there is any play or "rocking" in the wheel, you might have a bad bearing, bad strut, or bad ball joint. Rocking in the horizontal direction (grabbing the left and right side of the wheel) might indicate a bad bearing or tie rod end. Check for grease around the CV boots.

 

[jpark]

I had a '99 Explorer with the same noise, after around 25,000 miles. It turned out that one of the pads was frozen solid in the caliper, so it also made a thumping sensation, whether the brakes were applied or not.

I replaced the rotors and pads, and that fixed the noise and the thumping.

 

[jonas1022]

But not the calipers?

I should think that if it's squeeking too much(all the time), it would be the bearings being dry. If the brakes were the problem, imo it would stop squeeking when the brakes were applied.

Also, if the rust is the problem, whey doesn't it do that on other cars all the time. The disk corrodes on all cars, there is always rust on them.

Just some thoughts from a non-mechanic.

 

[jpark]

The calipers were fine. The tabs that held the brake pads in the sliding part of the caliper were corroded to the point that the sliding part of the pad was "locked" in place. I've never seen that happen before, or since. The new pads moved freely after I installed them.

 

[Surfscape]

Actually, the pads should normally be contacting the rotor. If you were to completely lift the pads off, you would end up with a very low brake pedal.... quote]

I guess I have to be quite specific in my advice or I'll get corrected. When I say the pad should not be contacting anything that would be they should not be contacting anything or contacting with force enough to create a squeak. (A gap of thousandths, not inches) They do ride on or close to the surface of the disk but with no real pressure if they do contact at all. I have built up many brake sets where the pads had clearences after set up and the peddle is in the proper location.

 

[stone]

I had my drivers side wheel bearing replaced. Mine was more like a humming than a chirp type sound.

 

[Davis137]

I already know that the wheel bearings are fine, as they were inspected the last time the truck was on a hoist in the shop (this was about 3 weeks ago). I was told by another dealership that the type of brakepad material used on these trucks will glaze if it gets soaked and then sits for a while (well, they will glaze after using them hard after sitting damp). I was told to go to a back road and do a bunch of panic type stops with the truck, not to engage the ABS, but strong enough to load up the brakes and suspension. They said this will de-glaze the pads (and yes, I waited 5+ minutes between each hard stop to let the brakes cool off).

It's all rather irritating...only had this truck for about 5 weeks now, and it's been into the shop 2x...

 

[Scooter Scott]

Davis do you have an update on this? Did the emergency stops work?

 

[Davis137]

No, the emergency stops didn't help (though they were indicative of how GOOD the brakes are on these trucks with 4-wheel discs). The sound still remains, even with new tires installed and balanced, and the truck has been in the shop again (to have the front-left swaybar link replaced). The wheels have been taken off, and the brakes given a looking over, and nothing indicative of uneven wear. Next step is to have the bearings pulled and re-greased, along with a full brake inspection, and possibly pad and/or pad and rotor replacement for the front, and pads only in the rear. The chirping sound is driving me nutz and makes my truck sound/seem like a piece of junk.

I'll leave an update on this when I get things looked at some more.