Here is the story. My machine only gets occasional mostly utility type use. I started noticing that it would develop a bad "growl" in the rear. Upon further investigation I discovered the rear brake pads were shot, and the rotor badly scarred. I bought a new rotor and pads along with the mounting bolts and protective boots. I installed the new rotor and pads and reassembled everything. Problem solved! NOT!!! It was fine for a short time. Maybe 5 miles. Everything was as it should be. Grandkids like to ride it now and they were riding it around the property. Came in and said it's making that noise again. I checked and it definitely was so they parked it. New rotor had a twinge of blue from getting hot. So has anyone else had this issue? What I am thinking I need to do now is replace the caliper assembly with a new one. I haven't inspected it closely yet to see if the rotor is ruined. I hope not but it is what it is. Am i better off to replace the assembly and be done with it? Any input is appreciated. Thanks in advance.

I've had experience with the e-brake setup but not the wheel brakes - but by your own description it sure sounds like the caliper is hanging up. If additional research/comments don't offer any revelations I would bite the bullet and replace entire assy.

First try and remove caliper take pads off and clean or blow out or shake out any gravel,dirt, or anything that might b trapped in there. Last year in utah i would have sworn rhinorats brothers 660 rearend was comming apart and it was just junk trapped in caliper behind pads


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I would drop the caliper down remove the pads and make sure the pistons are screwed all the way open and try that before going all new. My 05 and my brothers 07 had same problem and pads cured it without changing the rotor.

I had the caliper completely backed off and everything clean when I re-installed everything. It might be related to the parking brake too but I think I probably would be better off to replace the assembly. The only question I have concerning that is if it's the bare caliper or if it comes complete with pads and shims.

Sounds like it worked okay after repairs until a few brake applications then went back to noisy - sure sounds like a caliper hanging up. Not real familiar with your vintage so I have to ask - are the calipers mechanically operated (like the e-brake) or hydraulic?

The parking brake is mechanically engaged by cable and the main brake function is hydraulic. I suspect that the piston isn't releasing enough and the brake pad is dragging to much on the rotor creating heat.

That's what it sounds like to me. How nasty does the fluid look?

The brake fluid looked okay. It was not dark.

Any possibility the grandkids drove it with the parking brake engaged?


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That was the first thing I checked when I investigated the noise. It was in the released position and I'm doubtful they even know it's there. I'm thinking just to cover all bases I will replace the parking brake cable as well.

I had an issue with a replacement caliper that was not OEM. it leaked fluid. so get the OEM one. I would see if the parking brake is adjusted properly or possibly even left on by the kids. Also, when the replacement caliper leakes\d I just cleaned and lubricated the old caliper and reinstalled it.

I'm getting genuine Yamaha parts.

So in an update to the story. I replaced the entire caliper assembly brand new with OEM. New pads, shims, everything and a new parking brake cable just in case it was somehow guilty. Same results. After 15 minutes riding the rotor is very hot and the brake is chattering even though the brakes haven't been applied other than to start in gear. So now I am replacing the flexible and steel brake line that comes off the master cylinder. That's really all that's left. The front brakes don't cause any issues and it's a single master cylinder feeding all brakes. So if it were the culprit it should affect the front brakes too.

You need to check the hydraulic brake line. I’ve seen hydraulic lines start to come apart internally and rubber block the passage and act like a check valve not allowing the pressure to release. I currently have a Kawasaki ATV with that problem on the front brakes.