i was riding yesterday and my rear brake locked on ,the pedal stayed half way own,and smoked tthe brake pads,,,i finaly got to a spot i could stop,let the brakes cool, and smacked the caliper a couple times ,and it released,,i now have no back brake ,,,should i look at the caliper or does this sound like a master cylinder issue,,,,,its on a 1987 flhs,,i just had a tire put on about 2500 miles ago ,and my wrench said i had over half pads left,,,,,any ideas ??

 

Sounds like you seized a piston, notice any brake fluid on the caliper/wheel before the problem?

 

yeah, you're gonna need new pads. if you scorched them that much, then they are definitely glazed and will give you zero stopping power.

BUT, before you do that, you need to do some maintenance on your calipers. it could be that there was just some dirt accumulated around the pistons that would not let them retract. so start off with a good cleaning. and go from there.

 

Calipers need cleaning (thoroughly) at least every other year.. figure once every 20K at least. The pads slide on pins and the pistons push them in and then they ride the pins back when retracted. There are small clips that also keep the pads aligned sometimes one of the clips gets misaligned.

It's easy to do to take them apart and clean them, if you don't take the pistons out.

 

Might want to check the rotor to make sure you didnt warp it

 

The pedal should have returned regardless of the position of the piston in the caliper, I'd do a complete inspection of the system starting at the master. Did your wrench do anything to the rear brake system? Add fluid?

 

Agreed, but interesting thing is that the brakes stayed applied. If the pedal didn't spring back BUT you stop applying pressure then really by rights I would expect brake pressure to decay, at least to a point where perhaps the pads were only binding lightly.

Sounds like an all round clean out is required