i just picked up a 1991 kx250. The front disc break caliper is not releasing after 10-15 pulls. I have to crack the bleeder to get it to release. I've replaced the fluid thinking it may have been old and took on moisture. Didn't help. Went on a ride and same issues. If it were a car I would assume it was a collapsed break line. Before ordering a new line I thought I'd check to see if there were any other things it may be. Thanks in advance.