citation38

For about the first 10 miles or so in the morning at about 60 mph I experience what feels like badly out of balance rear tires. At around the 10 mile mark the hammering starts getting softer and is totally gone in another mile or so and stays smooth for the rest of the day. Tire rotation made no difference, still in the rear end only.
Also, intermittently during the day I may get what feels like a right rear disk pad dragging and releasing when moving very slowly as in when creeping toward a stop. This is accompanied by a "squishing" sound that maybe sounds like rear tire tread separation, also not affected by front to rear tire rotation, stays in rear.
Any ideas??

94 PEP 114,000 miles

rx7rcer09

sound like a variation of rear end problems, check your E-brake cable along with your brake fluid. you may need to bleed the system, also check your diff fluid it may be old and in need of a change.

citation38

Changed diff gear lube. No help. Rear brakes are not always totally releasing. E-brake not causing it. Bled rear brakes, no help. Could the master cylinder be causing this? Front brakes are fine, no drag. There doesn't seem to be a master cylinder repair kit for FD3S. I hate to spring for a new master cylinder one on a hunch. Problem is still intermittent, OK in the morning but rear brakes begin dragging later on. Rear wheels are much hotter than the front to touch. Maybe the calipers are not releasing but both wheels? Seems unlikely. Maybe any good brake man could fix this. I'd rather take her to a rotary guy that knows the FD3S but haven't found one in Orlando area so far. Not really a rotary problem anyway.

Roy
94 PEP

OKI92FD

If you can, park the car on level ground. Chock the front tires, put a jack under the diff and raise her up until the rear tires are off the ground. Put jackstands under the rear jack points if you can, but if you can't, the jack will be ok, just watch your hands. This test will take only a minute or two.

Once the rear is up in the air and the car is stable release the e-brake. Then you can safely rotate the rear tires by hand and listen for the noises you're experiencing. You should be able to hear if your rotors contact the pads.

If they contact the pads constantly you have a brake issue, could be anything. If they contact at certain points throughout rotation your rotors are warped and need a resurface. Hope it helps.

DaleClark

iTrader: (55)

The hop and weirdness when the car is cold sounds like a bad rear tire. As the tire heats up from driving it goes away, I've seen that before.

The brakes could be the calipers sticking, you could rebuild the calipers or pull the pistons out and clean them up.

Dale

citation38

Yes, I am thinking the two problems are unrelated. As to the first, I've already rotated the tires and the problem remains in the rear. I don't think it's a tire.

I think you're probably right on about the calipers, just seemed odd to me that both rear calipers would be sticking at the same time. Both rear brakes are dragging after they warm up.

I think for now I'll attack the brake problem and go after the other after this is resolved. Thanks much for your input. Much appreciated.

citation38

I've already done what you suggest. The brake drag is constant and is the same on both rear wheels. That's why I was wondering if the master cylinder could be causing it to the rear wheels only. I guess it could be both caliper pistons sticking when warm. Thanks for your feedback.