hi guys, reelal here, a newbie.
i have a1982 chevy 4x4 6.2 diesel with a sticking right front brake.
have replaced the caliper & the hose bled it and it still sticks. could
the proportioning valve cause this? when i replaced the hose fluid
did not run out. if it was the master cylinder would not more than one
brake lock-up? any help would be appreciated.

 

Did you clean the surfaces where the caliper slides on (The guide pins) And lubricate them?

A bad master cylinder usually goes to the floor.

I think a proportioning valve would be either a front or rear problem not just one front hanging up

bleed the whole system. and see if that helps.