[spencers]

Hi all,

I changed my rotors back in June and I've been unsuccessfully diagnosing a squeak that developed right after the swap. They are Zimmerman CoatZ rotors from ECSTuning.

The squeak is audible at all speeds, and only comes from the rear passenger side. It does not go away if I pull the e-brake while driving but it DOES go away when I brake.

I first thought it was the brake pad sensor, so I removed it and tucked it away under the fender liner, but the squeak is still present. I've yet to reinstall it.

Then I thought it was pads, so I swapped the Akebono pads for Hawk ceramic pads, but the squeak is still present.

I've also cleaned the guide pins and re-applied CRC brake disc quiet paste each time I removed the caliper/pads.

I'm at a loss! What could it be?

The sound is VERY similar to this random youtube video I found.

[juld0zer]

Handbrake is adjusted improperly.

[SpartaEvolution]

It could be as juld0zer said, or maybe a bent heat shield. If there was crud on the hub or rotor mating surfaces that could also cause the some rubbing.

[spencers]

Yesterday I cleaned up all surfaces with a wire brush. Hub, caliper carrier, parking brake shoes, etc. Unfortunately squeak is still present.

I also Ferris Bueller'ed it and the squeak is not present when the car is in the air. It's only present under vehicle load and while driving a straight line. It appears to cease when taking a curve and not using the brakes. Does this change what it might be? The hub itself has no play when I rock the rotor side-to-side or up-and-down (my typical wheel bearing test).

Up next I may try adjusting the parking brake, but I'm having trouble understanding how it would help at this point.

[juld0zer]

This is not a very scientific test but get the rear of the car up in the air and chock the front wheels. Take the wheel off the suspect side and get some washers or a wheel spacer and snug it down using the stock lug bolts. The idea is to get even pressure on the rotor hat.

Get an assistant to rotate the tyre on the opposite side while you watch the rotor rotate in relation to the dust shield or some stationary reference object. Take note of any oscillations or distortion in all directions (look towards the vanes and directly from the side)

Another idea would be to swap the rotors side to side and go for a drive to see if the issue follows the rotor.

Do you have the caliper springs fitted properly?

Calipee carrier bolts properly tightened? They have threadlock on the ends and are supposed to be replaced but you can get away with reusing them, tighten firmly using a 2ft ratchet. Just don't torque to 110Nm or they will break.

What part number are the rotors?

Wheel bearing failed? Do you have mechanics stethescope? Or you could flintstone it using a long screwdriver and listen with the car spinning the back wheels in the air.

Upload some photos of the suspect side also as that might give us some pointers.

Some ideas i also ruled out but worth checking:
- Outer CV gaiter (rare for the rears to squeak)
- Tyre rubbing shock or another object (you didnt mention change of tyres etc)
- Debris in pad (you changed brand of pad and the fault continued)
- Bad pad batch (same reason above)
- Outer pad fitted inside out (rare to make same mistake twice. Mistake visually obvious)
- Handbrake dragging (usually unaffected by foot brake application but can be speed dependant)
- Handbrake mechanisms fouling inside rotor hat (same reasons above)

[spencers]

Originally Posted by juld0zer

Another idea would be to swap the rotors side to side and go for a drive to see if the issue follows the rotor.

What part number are the rotors?

I've been contemplating swapping the rotors side to side to see if it follows. If that's the case, It's an easy fix.

Rear rotors are Zimmerman CoatZ 336x22 purchased from ECSTuning in June. Part number 34216855004
https://www.ecstuning.com/b-zimmerma...4216855004kt1/

Thank you for all of the ideas above. I'll have to weigh them all. Really want this squeak to go away.

[spencers]

Back in town and attempted rotor swap from side to side. Unfortunately the squeak is still present at rear passenger. Same exact noise as before.

Really struggling to figure this out. So annoying.

Edit: I just used my power bleeder to bleed the brakes again. Squeak still present.

Edit2: It’s not the heat shield either.

[SpartaEvolution]

I assume the sound changes frequency based on wheel speed? Is there any abnormal wear (grooves or discoloration) on the pass. side rotor vs the drivers side? I can't imagine you'd miss this having swapped pads twice, but could there be a rock wedged somewhere in the caliper? Did you re-bed the rotors/pads each time? I'm getting annoyed just reading about this problem, I can't imagine how frustrated you are with it!

[spencers]

Originally Posted by SpartaEvolution

I assume the sound changes frequency based on wheel speed? Is there any abnormal wear (grooves or discoloration) on the pass. side rotor vs the drivers side? I can't imagine you'd miss this having swapped pads twice, but could there be a rock wedged somewhere in the caliper? Did you re-bed the rotors/pads each time? I'm getting annoyed just reading about this problem, I can't imagine how frustrated you are with it!

Yes, the sound changes frequency based on wheel speed. Slow squeak when moving slow, then fast squeak when moving at 45mph+.

I've checked the caliper numerous times. I haven't noticed anything wedged in there.

I think at this point I'm done DIY-ing this issue. I've run out of time to spend at the cost of family time. I'll take it to the dealer and hope they can provide an explanation.

[SpartaEvolution]

Good luck, and keep us posted.

[e90Jeet]

Originally Posted by spencers

Yes, the sound changes frequency based on wheel speed. Slow squeak when moving slow, then fast squeak when moving at 45mph+.

I've checked the caliper numerous times. I haven't noticed anything wedged in there.

I think at this point I'm done DIY-ing this issue. I've run out of time to spend at the cost of family time. I'll take it to the dealer and hope they can provide an explanation.

Do let us know what dealer says ... I am in the same situation . Thanks

[Ubersmooth]

I have a similar sounding squeak. Seems to only happen in first and second gear at low speeds and stops when my foot is on the brake. Also seems to only occur when my car is warm. I've heard that it may be the brake pad sensor in the rear?

[spencers]

Here's my followup. I took it to the dealer this week and had the shop foreman ride along to hear the noise.

They just returned my car back to me and the squeak is gone! Here's what the service sheet says:
"Test drove vehicle multiple times. Found noise coming from the right front wheel area. Found after market brake pads making noise inside the caliper slide. R&R caliper and caliper slide, clean all pad contact points and lubed with brake pad paste. Reassembled vehicle, test drove with shop foreman. Noise now gone. If noise returns, recommend replacing pads with factory pads."

TLDR: Noise was coming from the front because of contact points with "after market pads." Damn these Hawk ceramic pads.

[GATORB8]

Originally Posted by spencers

Here's my followup. I took it to the dealer this week and had the shop foreman ride along to hear the noise.

They just dropped my car off and the squeak is gone. Here's what the service sheet says:
"Test drove vehicle multiple times. Found noise coming from the right front wheel area. Found after market brake pads making noise inside the caliper slide. R&R caliper and caliper slide, clean all pad contact points and lubed with brake pad paste. Reassembled vehicle, test drove with shop foreman. Noise now gone. If noise returns, recommend replacing pads with factory pads."

TLDR: Noise was coming from the front because of contact points with "after market pads." Damn these Hawk ceramic pads.

Amazing how brake noise can sound like it's from a different corner. I've gone as far as replacing the freaking hub on the wrong corner.

Hopefully the dealer didn't stick you too bad on the bill.

[spencers]

Originally Posted by GATORB8

Amazing how brake noise can sound like it's from a different corner. I've gone as far as replacing the freaking hub on the wrong corner.

Hopefully the dealer didn't stick you too bad on the bill.

Only charged the $135 diagnostic fee.

They included quotes for misc things that the car still needs:
OFHG $506
Oil pan gasket $1132

Yeah I'll DIY