garados

iTrader: (3)

Alright, here's the deal.

93 Miata
NAPA rear pads
NAPA rear discs

A while ago, I had Hawk HP+'s on G3000 Spec Miata rotors. One day, with slight pedal pressure, they'd make a resonance that could be heard and felt throughout the car. With more pressure, the resonance would go away. In my mind, this is a warped rotor ... but wait, there's more.

This is when I replaced that setup with the NAPA pads and discs (with miata rear brakes, the manual caliper retractor needs to be adjusted to 1/3 - 1/2 turn retracted from initial pad-rotor contact for proper operation). The slight-pressure resonance went away, but eventually came back a few weeks later. It's not as bad this time around, but it still came back. I know it's the rear because when it starts to resonate, I can keep pedal pressure and pull the e-brake and the resonance will go away. I believe it's on the driver rear (I could be wrong).

Here's the kicker and why I'm still scratching my head about this situation. When I first start driving the car, I can do any kind of braking: light, medium, hard, oscillating between those states, anything, and it won't resonate. Occasionally, after driving on the freeway or doing a couple hard stops (there's some heat in the brakes now), then the resonance will come back and act like a warped rotor.

If it is indeed a warped rotor, what would cause it to come back? This weekend, I'm going to remove the caliper, clean the sliders, regrease them, readjust the caliper, and see if it helps. Could a failing caliper cause this to happen? How about a warped hub (is that possible)?

Thanks for the help!

ragingti

If the caliper slides aren't free, it could cause you're problem.

thesmogman

I don't know for sure. I am not a brake man but I heard for resonating brakes you can take off the leading edge of the pad to a 45degree angle.

You do have the backing plates on with the non-squeek stuff between the pad and the backing plate. (If there is one?)

garados

iTrader: (3)

I got the car without the backing plates and new pads don't come with them. I put the antisqueal on the backs of the pads (against the "fingers" and the piston) and I don't recall if it seemed to help the problem. I'll check that out tomorrow ... thanks for the suggestion!