Front Brakes are locked up. THis is where we started. I replaced the rear Drums and cylinders about 3 months ago when I put the New Rearend in. After I finished installing new motor I took it for a test drve and came back and smelled the front brakes. Jacked the car up and I could not turn the Front wheels. THe rears work fine I step on the Brakes the tires do not move I release the Tires move. So I replace the 2 Front calipers and the same thing. So I replaced the Master Cylinder still the same thing. If I release the Pressure by opening the bleeder Valve the Brakes release like they should it seems like the Fluid is only going into the Front Caliper and not being able to come out. I guess I only have two parts left. THe Booster but I figured if the booster was sticking then all 4 would lock up. Or the Proporsioning valve????? And help is greatly appreciated. THanks in advance

 

THe only thing left that it could be is the proportioning valve.