Kidney

I've been fighting this problem on my 92 f150 for a while now (300,2wd,5spd,longbed). When the truck sits the rear brakes lock up, or at least one of them does. Once I get the truck moving, which can cause the tire to drag for a few feet, it goes away and brakes like normal. However, if I park the truck for even a few minutes, when I get back in, the rear is locked up again. Thus far I have replaced both emergency cables, brake shoes, springs, cylinders and leaky axle seals. I would hate to think that the new emergency brake cables are bad, but when I changed them the last time, it looked like someone already changed one out. So I changed the original one with a new one, but as it turns out the previously changed cable was already bad. I'm really at a loss as to what I can fix or replace now. Any advice would be greatly appreciated.

TIA

NGM

When its locked up check to see if its a fluid issue by opening the bleeder on the wheel cylinder. See if it shoots fluid out and releases the brake. IF it does then wait for them to lock up again and break the line loose at the master cylinder for the rear brakes. If that releases pressure then its most likely a bad master. If the pressure does not release at the master then go to the proportioning valve and see if the pressure releases on the line leading to the rear brakes. If it does then its a bad proportioning valve. If not then I would suspect a collapsed brake line in the rear. Probably the rubber line on the axle.

Kidney

Thanks NGM....I tracked it down to a collapsed rear brake line, or at least I hope that's it. Right now I'm trying to track down the driver side brake line, that has two different fittings on it. If not I guess I'll have to roll my own brake line.