rear caliper got hot and stuck on

[Kentish]

Anyone know why my caliper got red hot and the pads stuck on? I recently bled the rear brake and put new pads in? could to much fluid cause this to happend? once it cooled down it was ok...

[darrsi]

Seized pistons the likeliest culprit, you can start by pushing the pistons out a little bit then giving a good scrub with a toothbrush and brake cleaner, then smear the pistons with red rubber grease.
Normally caused by baked on brake dust, or simple neglect.
If that doesn't work then it'll need a proper overhaul and clean up with new seals too.


If you put the bike on the centre stand does the rear wheel spin freely, or is it rubbing badly?

[darrsi]

Another little tip, give the inner pivoting joint of the rear brake lever a good spray with either brake cleaner or even WD40.
If you haven't done it before you'll see a load of shite come out of the joint.
I then use 3 in 1 oil on the joint to lube it, but you can use whatever you want really.
It makes the rear brake much more responsive when it's all cleaned up and oiled (as long as your caliper is functioning correctly)
I clean mine once a month, you'd be surprised how quickly it clogs up in crappy weather!

[Kentish]

what about putting to m uch fluid in though?

[darrsi]

what about putting to m uch fluid in though?

That certainly wouldn't help, if there's way too much the fluid will expand with the heat and have nowhere to go so could cause the brake pads to drag!
If you feel this is a possibility then simply take a bit out.

[69oldskool]

My two pence worth.

Most Likely sticky pistons,
                                  but could still be air in system?~the air will expand when hot after using brake pushing pads against disc,then stop doing so when cool.

Rear caliper's a bit of a pig to bleed IMO,so worth checking.

[darrsi]

Does the wheel spin freely on centre stand or does it bind a lot?

[Dead Eye]

I can't see this being too much fluid myself as the master cylinder should prevent this shouldn't it?

[red98]

yep...sticky pistons here too....with the new pads fitted your now using the part of the piston that was exposed to the elements when the worn pads were fitted  ...a good clean up should solve your sticky problem 

[darrsi]

I can't see this being too much fluid myself as the master cylinder should prevent this shouldn't it?

Depends if it was topped up when the last pads were low, then new pads were put on.
Unlikely, but possible.

[red98]

thats the reason for two level lines on the master cylinder,to allow for pad wear 

[darrsi]

thats the reason for two level lines on the master cylinder,to allow for pad wear 

Yep, that's why there are lower and upper levels on coolant and oil too, they're put there for very good reasons