Rear Brake Locked Up

I was out riding today when the rear brake locked up on me. I wasn't moving very quickly when it happened and it didn't cause an accident or anything, but it was difficult getting back home as starting from a stop required lots of throttle and burning the clutch. Pedal was firm like it had been pumped up (like when you're bleeding the brakes). When I got home the rear caliper/pad was smoking. I was able to unlock the brake by cracking open the bleed nipple. The rear still feels like it's dragging. Any suggestions?

I would try flushing the fluid and bleeding it to make sure there is nothing funky in the line. If it still hangs up, I would guess a problem with the master cylinder or caliper piston assembly.

One other thing is to make sure the caliper assy is free to slide on the pins. My wife;s car started dragging the front bakes and it was because the grease they used on the pins had congealed and was hanging up the caliper. As the pads got hot and expanded, the brakes would drag.

Would also adjust brake rod for more gap before contacting m/c piston upon depressing brake pedal.

Good Luck!

check the little supply/return hole in bottem of mastercylinder to see if its plugged with something not allowing fluid to return.also check your brake pads and flush your fluid as im sure all that heat didnt do them any favors

If you could crack the bleeder and release the pressure it sounds like a problem with the master or line. Sometimes a softline can break down internally and get what acts like a check valve inside of it. To narrow down between line or master, try cracking the line loose at the master and see if it relieves pressure there. If so, suspect master. If not, suspect line.

Thanks guys, I'm going to get into it tonight and I'll report back.

well whats the news?

Drained the brake fluid and refilled/bled the brake. Took it for a quick spin around the block and everything seems normal. I need to test it when it's really hot out like it was yesterday when it locked up. I'm almost wondering if the old brake fluid was breaking down and expanding in the lines. The fluid appeared to be in pretty bad shape. I went back with DOT 4 that should hold up to more heat.