brake problem

[gafiredog]

hey guys, need your help! i bought a 1975 c-10 step, one owner, out of a barn. been sitting for 7 years. got it running no problems, did a complete brake job, new wheel cyl. , new calipers, new master cyl. everything new. my problem is i'm getting good line pressure to all the wheels except the L. front. the pedal has to be pushed really hard to get fluid to come out the bleeder. after bleeding it, & tighten the bleeder valve, then pump the pedal, the caliper won't release the rotor to turn freely. it only does this on the L. front. the only thing i can figure is the pressure valve on the very front cross member under the radaitor is bad. any ideas ???? thanks guys, Art