Front Right Brake Dragging.

My front right brake has a slight drag, Ive replaced the ruber hose and brake caliper. I blew air through the steel line also to check for a clog there. All other brakes are fine. When brake is dragging the pedle has little to no play and is firm. However if i let it sit for a while say 30 min the brakes seem fine i can move the brake pedal a couple of inches (pedle feels normal) , there is some brake squel.

When i disconect the brake line from the right brake caliper the brake fluid will not drip out. I ve bled all brakes. 4-5 times allready. Could there be air in the system??

Im not sure what else to do. Maybe try a new master cylinder but i doubt it will solve the problem.

This also only occurs after driving for 5-10min or so and does not happen right away in the morning.

2 calipers and the same problem
im getting frustrated, i was sure it was a caliper too.

I have a 91 B2200

there is a proportioning valve on the firewall under the master cylinder.check and be sure one of those lines isnt kinked.bj

depemds on the year of the truck your valve might be on the pass side fire wall