Problem with 1985 Tri-Z rear brakes

[bushwacker51]

My exchange student Frank just bought a 1985 tri- z. He took it for a spin then I jumped on for a ride and the rear brake caliper locked up. The mater cylinder piston would not move. I had to losen the rear brake line to allow some brake fluid to run out then the caliper released the pads and the brakes started to work again. I called the guy we bought the trike from and he said it did that about a year ago and he rebuilt the caliper and put a new brake line on and it has not done it since. Any ideas what the problem is ?. Is it the master cylinder, The caliper or is there junk in the lines. Any help would be appriciated. Thanks Glenn Oister :cry:

[TimSr]

Sometimes a master cylinder can do that, but first thing I would do is flush out the lines. Brake fluid quickly grabs and holds moisture when exposed to atmosphere. When your fluid is contaminated with moisture, it will swell when it gets hot, and cause this problem. If it were the caliper, it would not have released when you loosened the line.