Brakes

[Jason Dement]

I have a 07 nbs 2500hd duramax.  The right front brake locks up after first start of the day. Can only go about 2 or 3 miles and it locks up. I get out turn the bleeding screw on the wheel and it relieves the pressure.  I can drive the rest of the day no problems. I have changed caliper and line still same thing.  What am.i missing? 

[davester]

by line do you mean the hose between the hard line and the caliper?