2004 F150 4x4 Lariat Screw - 56,238 miles

Went to back out of the garage this morning and my right rear wheel was dragging pretty bad (did a brake job on truck 4 months ago placed Power Slot Cryos on the rear with Hawk Performance Pads). Figured it was the caliper so took the wheel off, jacked it up, put it in neutral and could not spin the right rear wheel. Took the caliper pins out, slid the pads out and was able to push the piston back in. Replaced pads, mounted wheel put in reverse and wheel dragged in reverse but not going forward. Inspected the emerg brake cable and tested this, seems to be working fine.

Opened the bleeder on the caliper for about a minute, fluid was really bad looking, closed the bleeder and put the truck in reverse, no dragging. Drove the truck for about 10 minutes around town with no problems so I'm kinda stumped.

Talked to my mechanic friend and he said its probably something in the drive train. Suggested I drop the oil and look for metal fragments. I did check the fluid, was pretty dark and smelled a little burned. Should I drop the diff fluid this weekend or do you think its a brake hose problem. I have heard they deteriorate from the inside and can cause a vacuum lock at the caliper....

Suggestions?

 

sounds like problem with line or caliper,check steel line and hose to wheel for damage,also a good idea if fluid looks discolored to flush it.