I've got a horrible, horrible sound coming from the rear. It's a nasty grinding sound that is sensitive to the brakes in that it changes in intensity and tone etc.. as I use the brakes. I can hear the sound even while cruising, reflecting off the median walls on the highway, off of other cars, etc. I wouldnt say it is constant because at times I dont hear it at cruise, but every time I use the brakes it lingers afterwards, it's there off of a stop, its there during / after turning. Hell it'll be there after a bump in the road.

At first I thought wheel bearings but both left and right check out with absolutely no play up, down, left, or right; on the ground and off the ground.

Further inspection showed that with the rear end up in the air (e-brake on) the rear wheels still spin! Not easily, they grind as they do so and the e-brake is it's own issue.

Could a stuck or dragging caliper cause this sound? What should I look for here?

RX-7's are the first cars I've ever worked on and I'm getting pretty good with them, I've done a lot of engine, clutch, transmission, electrical work but I have never really messed around with brakes or suspension before other than changing pads.

Thanks for the help guys!

 

Sounds like the pads are sticking. How old are the pads? Whats the run-out on the rotors like? Are they warped at all?

 

I'd remove the calipers and clean/lube the pins they slide on.
When reinstalling, leave the ebrake cables unattached (tie them up out of the way) and then test drive it.
If the noise has abated, replace the cables (wouldn't hurt to lube them and the actuating arms they attach to) and see what happens.

If the noise persists, rebuild the calipers- it's an easy ten minute procedure.

 

I have no idea how old the pads are, Im waiting till payday and Im putting new ones on all four wheels. I bought the car in June and rebuilt the engine over the last few months. Now that it is back on the road Im finding out what else is wrong with it.

I think it's the left caliper, the right one doesnt make any noise at all and the e-brake seems to stop that one.

Clokker, I'll do that tomorrow; while I'm at it I will check the rotors. Thanks guys.

 

Wow, well I finally addressed the issues here. Ashamedly I drove the thing until the rear driver caliper locked up, yup I am a lucky idiot. After inspection I had to replace the rear caliper, rotor and pads all around. After all that I still had a terrible grinding sound. It turned out to be that the dust cover was bent..... jeeesh.

All good now.

 

Dust cover, been there done that.