[supereal]

If the brakes "bind up" as you drive and use the brakes, usually the problem is the master cylinder "residual"valve. This keeps a bit of pressure in the system so you don't have to pump the brakes each time. A faulty valve will retain too much pressure, and apply the brakes as you drive. To be sure, put the car with the wheels off the ground and pump the brakes until they lock when the pedal is released. If all brakes lock, it is the master, If only one locks, either the wheel cylinder is corroded and sticking, or the return spring is broken or weak. Installing disc brakes is a big job requiring new plumbing for a proportioning valve. At our shop, we don't recommend going to DOT5 silicone fluid without replacing all cylinders and flushing the lines with alcohol.