Went for a short ride today and when I slowed down I could smell smoke ,I got off and the rear caliper was smoking,I let it cool for a bit so I could make it home which was 1/4 mile and when I pulled in the drive I was holding my breath,I could not see my rear tire for the smoke,I hosed it with water to cool it,thought it was going to catch fire "lol".I pulled the caliper and only one piston was working free,the other was all the way in,I split the caliper in half and the free one looked good and pulled out easy,I'm having difficulty getting the other out as said it is all the way in the bore,the 99 models do have a dual piston rear caliper correct? I have it soaking with wd-40.I the shop manual says use piston pliers? Anyone ever had a rotor/brakes smoking? What's odd is when it cools it does not stick?

 

Your right they are dual piston. You could possible have a bad seal in your caliper and when it gets hot fluid is building pressure on that side and causing that piston to push out against your disc. I think you can get the rebuild kit for around $20 that should replace all the seals in both sides. Hope this helps you out.

 

Thanks,I have it soaked in wd-40,tried channel locks and the piston will not not move,I doubt air will push it out.May try PB Blaster tomorrow,hate to use heat.

 

The only other thing I would know to try if you haven't already remove the bleeder screws and lines and take a c- clamp and see if you get any movement that way.

 

I was just thinking,I could reassemble and reinstall it,bleed out the brakes and leave the pad off the seized side and see if hydraulic pressure will push the piston out,looking at the rotor it had some movement.You were right,found a seal kit on $bay for $17.99

 

When this happens usually the either the foot brake master cylinder or the master cylinder is keeping pressure on the rear caliper. I've had this happen before. Didn't catch on fire,but warped a rotor. "IF" you're careful you can pop the stuck piston out using compressed air on the bleed screw hole. Just have a big towel wrapped around the caliper while it's on a work bench and use safety goggles. Had em sound like a 22 when the piston pops out.http://www.cyclepartswarehouse.com/f...1999&fveh=5486

 

Thanks OPT,It has done it twice before on the trails and I noticed alot of steam hitting water but thought it was the exhaust and during cleaning I saw the rotor was blue so it's likely warped.Will the front master cylinder cause the rear "only" to stick and not the front brakes seeing it controls both?

 

Can be either the front or small rear master cylinder piston sticking causing this. The ones I've had were from the front piston,even though it didn't seem to affect the front brakes. The small rear master cylinder for the most part bleeds down from non use a lot of times. After you get everything back together,just bleed both master cylinders and use both the foot and hand brake several times separately and see how it does. If the rear is sticking,the master cylinder has to be replaced,the front you can get a piston kit.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse