billyvq_uick

I posted this a while ago in the suspension and brake section because originally I had thought it was a brake issue. But now that I have new rotors and pads in the front, a new driver side rear caliper, rotor, and new rear brake pads on both sides, I'm still getting this issue, which leads me to believe it could be a tire problem. OK, without further ado.

I'm getting a "tapping" sensation in my foot on the brakes, as well as a sound when I'm coming to a stop. It does not matter if I'm braking or not, it still happens. It FEELS like it's coming from the front but I have no idea. The "tapping" matches the rhythm of the tire spinning (if that makes sense.) I'd hate to replace the rear tires if I don't have to, as the tires still have plenty of tread left. What could possibly be going on?

Any help is appreciated. Thanks!

dkmura

iTrader: (64)

It's almost impossible to troubleshoot a sensory issue from behind a keyboard. Is it possible this "tapping sensation" is an ABS issue? ABS will pulse a brake pedal when one of the wheels is locking up. This usually only happens in a hard stop on a slippery surface, but you may be encountering it on light braking if there is a fault.

Two thoughts: have you inspected the wheels and tires carefully? If there is anything wrong with them, you should be able to see it in the tread surface. Second, have you pulled codes from the ABS computer? There may be a code in memory that might help. Once you get it figured out, post it up in this thread. Everybody loves a mystery- as long as it's not about THEIR Z!

jhc

Have you jacked up each corner and manipulated each wheel/tire?
If you can isolate the corner, then unmount the wheel, see if the noise is still there. gl

MicVelo

Just a few considerations to add to dkmura and jhc's "virtual diags", which, as David said, is pretty much just guessing without putting hands on it....

- I think you're probably right on suspecting tires. It sounds to me (guesstimation) like an out-of-round/flat spot issue. Consult this chart while comparing tread wear....



You might want to try isolating the problem by having someone listen to the sound (if any) or evaluate the feel from passenger seat as you drive. If you can at least isolate which SIDE of the car it's coming from then you can "rotate" the tires F-R on that side and see if it either goes away or diminishes in intensity and/or sound.

Never mind the stagger..... you'll only need to drive a short distance to do this isolation.

Once you've done that, you can go ahead to look at possible causes, following:

- Suspect tires - could be flat spotted, out of round (happens more often than one thinks), excessively low/high tire pressure, funky alignment, bad balance of a tire going bad, internal tread sep. IOW, just about anything causing to the tire to NOT roll true.

- You mention brake servicing. Did you (or shop) check the front calipers for free movement? That is, one of your pistons might be sticking and the brake pad is rattling against the rotor (new or otherwise).

- Were bearings serviced? Could be a bad bearing. You should R&R those with any brake service, just because they're there, already half exposed. Zs are particularly susceptible to bearing wear if not properly adjusted. Since sound/feel is dependent of wheel speed, you need to consider anything else moving in relation to the wheels.

Good luck and report back - this will help others if/when that problem arises.

Mic