Strange Rear Brake Problem (long Post, Sorry)

[tinman]

Today I was driving I-90 into Chicago to help some friends move, when i noticed that my passenger-side rear wheel was making some strange "whooor,whooor,whooor" noises. I drove about a mile and it just got louder and louder. I pulled off on the next exit, walked around to the passenger side of the car but I didn't see anything of note. Then I put my hand on the rear fender above the tire and immediately some very hot air rising from the wheel. My wheel was spewing heat at a truly impressive rate. I licked my finger and touched the wheel hub, it actually sizzled! :o

I let it stand for awhile to cool and drove it over to a friend's place who has far more tools in his garage than I do. When we got it up on a jack, we noticed right away that there was brake dust all over the wheel -- much more than the other 3 --- and the outer pad was worn to almost nothing but the inner pad was still ok.

It looks like the caliper piston wasn't completely releasing and the pad was dragging on the rotor. In town this doesn't present a big problem, speed are low and it appears that the SC's vented rear disks are capable of dispersing a respectable amount of heat. However, at highway speeds, it sounded like it warped the rotor and obviously got way too hot. It couldn’t release the heat fast enough and just got hotter and hotter and louder and louder. Interestingly enough to mention -- the rotor looks just fine. It's not cracked or discolored. Also, I could push on the caliper piston and it retired back into the caliper piston housing just fine. I couldn’t push it back with my hand, but with a C-clamp it presented no trouble. I'm assuming that the piston is just getting hungup on something and couldn't release.

So, to make a long story longer, has anyone seen something like this on their SC before? I ordered new pads for the rear and a rebuild kit for the caliper. It should be here Monday.

I didn't wanna order anything else because i plan on upgrading the brakes anyway... and on that note, anyone know any good kits for the SC? AEM doesn't appear to make one and a complete Brembo "kit" is an ungodly 3 grand.

[AWJ]

I've kept my rear brakes stock and haven't had a problem of yet. I would recommend replacing both rear rotors. They are thinner and smaller. It is very possible either your rotor there is warped or like you said, the caliper is acting up on you. As far as brake upgrades, the supra TT stock brakes will bolt right in and very significantly increase the braking ability for much less than 3g's. I think that is the best way to go as far as brake upgrades. Otherwise, your looking at money. But Brembo, Wilowood, and Baer offer applications as well. I run Centric brand Sumitomo rotors. OEM spec. in back and they do great. Watch the torque on the wheels when you put them back on. Shops will just tighten the heck out of those wheels and that warps rotors fast. 75 ft lbs is adequate. I couldn't get my rear wheel off after the body shop had removed it to do some work. Had to take it to a shop with an impact to loosen the lugs for me. All the other wheels came off just fine because I had torqued them myself. I change wheels often though. Good luck.

[psolov]

Today I was driving I-90 into Chicago to help some friends move, when i noticed that my passenger-side rear wheel was making some strange "whooor,whooor,whooor" noises.

I've had a similar problem with my '95 Sc400 and it turned out to be the sensor on the rear tire (I believe the ABS but not sure..was 100K miles ago). It was locking up the caliper.

My .$.02.

Paul

[Dere2000]

I have a 95 SC and about 3 months ago I had to replace the rear calipers because they froze up. Along with that new rotors and pads. I am not sure the cause of this but it was not cheap. Oh well I guess it is one of those things. The thing that made me mad was my car had 19K miles on it.

[UCF3]

My 2cents. your rear caliper is seizing up. Your replacement caliper kit would probably take care of that. If not, buy some new one, and change the fluid. Better performance.

[johnny3]

Probably the caliper hanging up, sometimes the brake hose to that wheel brake will break down & collapse inside stopping the fluid from backing out making that brake stay loaded or applied, this happens more often than you would expect.

[Hain]

same thing kinda happened to me, but it just turned out that the shop that installed my new brakes didnt tighten the bolts all the way and a few fell off so i had to replace them and get those *BLEEP*'s to reimburse me, which still to today they havent mailed me my check yet...