khnitz

It was a busy Saturday. I installed a new RR brake caliper, new brake pads in the rear, and then in the front, and then bled the brakes. When I put the tires back on after all the repairs, I tightened them down and then went for the test drive. A little ways from the house, I realized that I had tightened, but not torqued, the wheel lugs .

I got back to the house and then torqued them down to the spec'd 85 ft/lbs. When I took another short drive - the drag noise from the brakes was considerably less.

After sitting over night, when I took the Z for a quick shake-down drive today it started off quiet with no sound of brake drag. But, about 1/2-way through my "test loop", I started hearing the light "swish-swish-swish" of drag. When I got back to the house, the brakes were nowhere near as hot as they were yesterday, but there was still the noise.

Here's a thought: could worn rear wheel bearings be contributing to the noise/dragging? Before I torqued the wheels down, the noise was prominent. That makes sense because tightening the wheels secures the rotors squarely to the hub and should center them to the caliper and pads. But, if there is more play in the wheel bearings, then the hub would be deflecting as well, along with the brake rotor and wheel, and then again be off-center from the caliper and pads and able to make noise & drag.

It's vexing...but I'll get it sorted

khnitz

I drove the Z to work this morning. Occasionally I heard a "swish-swish", but it was even again less pronounced today. When I got to the office, I walked around and felt the temperature at each of the wheels - none of them felt out of the ordinary, and they all felt about the same.

When I think on the possibility of the rear wheel bearings contributing, I think I would also be able to feel some play (even if it was slight) when I had the wheels off the ground to do the work this weekend. I don't recall any play in any of the wheels as I installed and tightened them down.

Maybe it is all just part of bedding the new pads (which I did do a bedding run when I first test drove the car after installing the new pads).

Aeneas137

take it all apart and redo it on the RR. your rotor probably did not get centered when you did that hacky tightening job on the lug nuts. take them all off come and make sure the rotor is centered and that the caliper bolts are nice and tight, then put it back together.

also thanks, you POS forum, for popping up a full screen ad when I was trying to post this and then closing my post instead of saving it.... as if this form isn't shitty enough now we've got full screen ads popping up in the middle of a post.

icer5160

iTrader: (4)

Hey khnitz,

Are you rocking the Brembos or Non-Brembo setup?

Not all brake pad kits are created equal, some of the included spring clips might not follow the OEM design, for the Non-Brembo front brakes, these springs are very important to prevent the pads from dragging. The orientation of the springs is also important. Correct orientation of the pad spreaders should be at the top of the caliper. For the rears, I don't remember if there were any pad spreader springs (non-brembo design), Sometimes these are built into the pad retainer clips (steel bits that snap onto the caliper mounting bracket).

I remember this came up not that long ago for another user, the focus was on the front brakes (LINK).

Looking at my FSM for the rear, non-brembo caliper/brake pad assembly, I don't see anything about pad return springs.

Things that come to my mind which could be causing your problem (assuming Non-Brembo Brakes):
1) Double check your caliper slide pins, if you got new old stock the grease could be dried out. Re-lube the pins and re-assemble.
2) Clean up any/all rusty crusties between your wheel hub and brake rotor, especially if you had to pull the rotor(s) off during the brake job. This rust can cause a noticeable amount of runout which will result in the symptoms you are having.
3) Don't rule out the wheel bearing, I just had one fail a few months back and there was zero play in the wheel/axle. The bearing noise was only noticeable with a load applied (vehicle's own weight) at freeway speeds.

Hope that helps!
Cheers!
-Icer

khnitz

@Aeneas137 @icer5160

I made sure to include that I made that mistake in tightening the wheel lugs in order to help a next person searching with similar symptoms.

My Z has the base, non-Brembo, calipers.

Thanks for both your advice(s?): I should remove the wheels, clean the hubs/rotor hats/wheel-mating-surfaces (I am in Michigan/rust-belt) and then re-install and properly torque all the wheel lugs again. Makes sense.

Thanks, again!