A friend of mine took his wheels off to change the tire and pain his wheels and spokes, and while they were off, he squeezed the brakes - I'm not really sure why - but the just stayed completely closed. When I went over to help him put them back on the other day, he had pried the pads open with a screwdriver.

The rotors went into the calipers fine, but now when he pulls the brake lever, the calipers close the pads down to the rotor and lock up - they don't open back up. I suggested cracking open the line at the caliper and prying them back open, which relived pressure, then we bled the line, but then it just did the same thing. I'm admittedly not familiar enough with brakes to troubleshoot this, so can anyone give me any suggestions I can tell him to try?

Thanks,
Jimmy

 

Well, the brake system probably needs to be bled again. He probably got air in the line. Another possibility is that the brake caliper piston had dirt or debris on it and needs to come out and be cleaned but more than likely it's just air in the line and bleeding should resolve it

 

The pads will close to the rotor and have light contact all the time. If the wheel is actually locking and you can't turn it, then it is probably debris, or possibly a burr or something from prying on it. Air in the line will make things spongy, but I doubt it would lock anything up.

 

Cool, thanks, I'll let him know. Anyone got any good tips for bleeding the rear line that can help reduce the chances of screwing up the new paint on his wheel? I've bled front brakes several times, but never the rear.

 

Hit the hardware store and get some clear tubing that will fit tight on the bleeder and run it away from the bike. And be ready with a bunch of paper towels and brake cleaner for the caliper.

 

BRILLIANT! Thanks.

 

Take the cap off the rear master when you pry the rear caliper open. I've had my rear brakes drag after not relieving the pressure after reinstalling the rear wheel. Probably the same thing your dealing with. Remove fluid if necessary