1988 Ford Bronco

Hi jgoodloe. Welcome to the forum. Bleeding isn't the issue. Air in the lines will cause poor brake application. It won't cause them to stick or lock up. Start by opening a bleeder screw at one of the wheels. If that brake releases, close the bleeder, and reapply the brakes to get it to lock up again, then crack open the steel line at the master cylinder. If the brake releases again, suspect brake fluid contamination. Proof will be seen by looking at the rubber bladder seal under the reservoir cap. If that seal blows up, is mushy, and is difficult to push back into the cap, the fluid has been contaminated with petroleum product. That will cause the lip seals in the master cylinder to grow and expand past the return ports. That prevents fluid from returning from the calipers and wheel cylinders.

If opening the bleeder does not release the stuck brake, it is likely you just have sticking pistons in the calipers or the caliper slides are rusted or impacted with mud. Ford products that use the rubber wedges to hold the calipers in place have a real lot of trouble with sticking calipers, but that won't affect the rear brakes. Clean those slides on the calipers with a file and use high-temperature brake grease on them. If the pistons are sticking, replace the calipers. We used to rebuild them at every brake job, but today professionally rebuilt calipers are very inexpensive.

Caradiodoc

Hi
Siicking do you mean draging wheel turns but with resistence? Or stuck on can't move vehicle? Any recent brake repairs? Can you open bleeder and fluid come sout then wheel spins free/
let me know
Thanks for donate

That's good news in a way when opening the bleeders has no affect. That rules out contaminated fluid which is a very expensive repair. Pop those pins out and see if the rubber is deformed or if it's ripped from the metal slides. If you have just the metal inserts that are held in with a bolt that uses a 3/16" (I think), hex wrench, clean those inserts on a wire wheel and lube the side that contact the caliper. Clean up the other end of the caliper and mount and lube them too. There really isn't much that can cause them to not sit straight on the mounts.

If the caliper is held on with two long bolts, rust pits will prevent the caliper from releasing smoothly. Check too if they are bent. That mounting system causes a lot fewer problems than the slides.

Caradiodoc