Stitch

Hello,

Just replaced the calipers, front pads and rotors on my 2000 XJ. I've put about 80 miles on them so far. When I give the brakes a heavy push I'm now hearing a grinding noise. The vehicle has about 190,000 miles and is in stock configuration.

Could this grinding be a sign of something else wrong with the braking system? I'm going to take it apart this weekend and inspect deeper. The noise only happens on heavy braking. (No anti-lock brakes)

The rear brakes were good the last time I checked. About 8,000 miles ago.

Any thoughts why this is happening would be great.

Thanks,
Stitch

thatXJguy

Grinding or squealing?

Did you lube them up properly?

Did you set (burnish) them?

Stitch

Thanks for the reply.

It's a grinding noise. I did grease them up. But DID NOT burnish the rotors. I figured the bed-in would be done after a few miles.

Are you thinking the process is still being done and the pads are still finding their groves?

I still have to take them apart. But, looking through the wheel at lunch time I see very little wear on the rotors.

thatXJguy

Depending on how the grinding sounds, a lot could be happening.

It is possible that a small rock or dirt particle(s) could be trapped and is causing the sound when you engage the brakes. You can check for this by looking at your rotors and looking for any kind of grooving or lines.

Since you didn't set them, the most likely scenario is that they have not set properly and you should really have the rotors turned again and then burnish them properly.

Some brake pads make more noise than others. Ceramic are the most quiet, while metallic make the most noise. What did you use?

There are very few moving parts in the brake system. That's the wonderful thing about brakes.

The only other thing you could check for is spindle wear.

Stitch

I think in might be a (dry)bearing issues too. Previously I did have the caliper over heat(smoke). That's why I replaced both calipers on this last project. Now, I'm thinking the grease might have melted... Just a guess.

If the bearings are dry would they vibrate under heavy breaking?

I don't hear any sounds coming from the brakes while NOT under heavy breaking. So that's good.

1976gmc20

My experience with disc brakes and bad wheel bearings (not Jeep) is exactly the opposite: the noise stopped when braking (presumably the calipers/pads held the disc/hub more straight and relieved some pressure on the bearings).


I'd be looking to make sure everything is back together correctly (though it is hard to mess up a disc brake job) and that no metal parts are accidently coming into contact with the rotor.