Rear brake issues..

[GaHyperOne]

Can anyone give any possible insight to this incident. . I was on my bike and I downshifted and braked front and rear for normal stop for a vehicle turning left. As he turned I resumed in second gear, but there was a definite strain on the engine, so downshift to 1st release clutch same thing, so I pull to side of road. The rear brake was stuck/ engaged. Attempt to check it out make sure brake arm wasn’t bent or anything funky like that. I did not notice anything unusual, but the brake released unknown why. But when the rear brake released brake arm was back to normal tension and motion, but this time there is no rear brakes. Decide to ride ½ mile down the road to store. Get off check fluids, looking for any leaks in brake system, nothing. But while checking these things the brakes began to work again, went to the house a few miles away with no further problems. OK any suggestions? I was wondering if it maybe the actuator/slave cylinder that is activated by the brake arm? Could it be going bad? Or any other solutions/ suggestions? Thank you for any assistance in advance.

[mrmekon]

If it's a hydraulic disc brake, I would check the caliper. If grime got in the piston boot, it can stick open or closed.

[Back Marker]

how many miles on the bike? what colour is the rear brake fluid? any leaks? caliper slide moves freely?
drain the fluid and check if you can push the piston back into the caliper (i use a c-clamp with the brake pad on).

-a|ex

[gbauto]

had a similar experience with the sv. turns out that the piston in the master cylinder got stuck from corrosion. you may need to remove the rubber dust boot where the push rod from the brake pedal goes into the m/c and see if the piston is moving freely when you push on the pedal.

[GaHyperOne]

ok update... I checked the fluid after was able to get home and fluid was little low but still at normal level, but added some to be safe. Checked out around neighborhood no problems. ventured out a little further, still no problems. So I ride from Jasper to Cartersville almost an hour drive open road for most part. But once I got into cartersville with the redlights and went through about 5-7 redlights, the rear brakes seized again. Once I pulled to the side of road, the fluid was being pushed back out of the reservoir. waited for a few minutes then released and again no brakes. then they returned once started down the road again. Caliper? Master cylinder/slave cylinder that brake lever actuates? fluid in res was clean. Again thanks in advance. everything seems to be functioning normally with the mechanical moving parts of brake.

[TLR67]

Back wheel could be out of allignment and rotor could be getting hot from rubbing a pad..

[wallypiper]

Heat won't apply the brake unless something else is wrong.

[TLR67]

Heat won't apply the brake unless something else is wrong.

No but the rotor can expand and make the back wheel quit rolling free... This happened on my 600 a couple years back..I put new pads in it a few days earlier... Went to put the tire warmer on at Tally and WTF???? Wheel was locked up...

[Back Marker]

i recommend not using the rear brakes until you get a tech to check it out. it would suck if it stays locked up on the road. i normally don't ever use my rear brakes.

-a|ex

[GaHyperOne]

the brake isn't applying at random I am applying it during normal stop and go between redlights but then it fails to release. then loses brake completely for a short time then back to normal. And the recent posts with tire alignment and rotor expanding this shouldn't cause it to bind then release to nothing then back to normal again, right? plus the back pressure causing the fluid to be forced out of reservoir. Thank you all for the input but this one has me baffled a little I'm pretty mechanically inclined but I'm left scratching my head hte way it sticks then loses brake and then to normal...

[TLR67]

i normally don't ever use my rear brakes.

-a|ex

+1.. Only in Grass and Gravel here....

[gbauto]

the brake isn't applying at random I am applying it during normal stop and go between redlights but then it fails to release. then loses brake completely for a short time then back to normal. And the recent posts with tire alignment and rotor expanding this shouldn't cause it to bind then release to nothing then back to normal again, right? plus the back pressure causing the fluid to be forced out of reservoir. Thank you all for the input but this one has me baffled a little I'm pretty mechanically inclined but I'm left scratching my head hte way it sticks then loses brake and then to normal...

you are going to need to do a little test to isolate where the problem is located. you will need a wrench that fits on the bleeder screw for the rear caliper when you go for a ride. when the rear brake locks up open the bleeder on the rear caliper and see if the wheel turns freely-if it does then the m/c or possibly the flexible brake hose is causing the problem. if it doesn't release then the caliper is causing the problem.

[BlueLghtning]

Have you started simple and done a full flush/bleed job on the rear brake? Brake fluid absorbs water as it gets older and usually darker in color. As you saw when you poured in new fluid, it should be almost clear. Its cheap and good maintenance to do a full flush and being that its only 1 caliper for the rear, its easy.

I would start by getting all the old fluid out and making sure you have fresh fluid from a "sealed" bottle (DOT 4). Before you do that, go ahead and pop the caliper & brake pads off and verify the pistons aren't binding or their is corrosion or other things that are causing the caliper to stick. Check the alignment of your rear tire as was mentioned.

Once you have everything back together and brakes bled, spin the wheel and then use the brake and release. See if the brakes are releasing or continue to drag after the pedal is released? If you still have problems here, then you have something a bit more major going on, but I would try these items first to rule out the simple things.