CPP power disc brake conversion, brakes dragging/locking up

[Blue Lepard]

Hi everyone. My wife and I just bought our first Chevy poject, a 1966 Chevt C10 short bed single cab. So getting right to it. I bought the CPP front power disc brake kit. I installed it. Everything was working nicely for about 20 min of driving when I noticed the truck felt slow. So when I had to do a quick stop, well she stopped fine. But when I let my foot off the brake. Nothing truck wouldn't go. Then I excelertated to make her go. The truck struggled but started. I could feel the brakes where still engaged. But after appoximately 5 seconds I could feel the brakes releasing a little. So I continued to drive. I hit the bakes again the truck stopped nice, the brakes didn't lock to a skid or anything. But when I took my foot off the brake. The truck did not go. I hit the gas and fought the brakes but after about 5 seconds I could feel the brakes releasing. Same thing all the way home. I did the usually,

1) checked the free play on the rod from the booster to the pedal, all good.
2) loosened the nuts off the master cylinder to the vacuum booster.
3) loosened the front brake master cylinder nut and let a little fluid out
4) loosened the front bake nut on the pro valve until a little fluid came out.
5) checked the calipers for missalignment
6) checked the rear brakes for brake shoes locking

NOTHING…!!!


While the truck was up on jacks, I hit the brakes (fluid still hot) and the front brakes locked up. Nothing I did would release them, except time. I waited about 5 minutes and walked over to them. Guess what they were free. So, with everyones experiance, what is going on.