I posted this earlier on different thread and should've started a new one since we seem to have soo many problems with the El Camino brakes.

65 El Camino 9" dual diaphragm booster, aluminum vette style master cylinder from Speedway, Wilwood adjustable prop valve only, 3/16" lines all the way around, and D154 calipers at all four corners.

Dustin's rear disc brakes just aren't backing off after releasing pedal. Dragging slightly all the time. I have the Wilwoood prop valve backed off all of the way. No other combi valve. Using an aluminum vette style mc from Speedway (you know...the one with the stainless valve) and the tech fella assured me it was for rear discs, but now I'm having my doubts. If it was a true vette style it wouldn't have any residual valve built in....correct? We're using the D154 style calipers in the rear. All new hoses. No crimps. I just see no reason that pressure wouldn't be released back to the mc. Oh, and I've triple checked pedal free play and rod length. Pedal doesn't move the rod on outside of booster until after a 1/4" of pedal travel.

How can I test rear portion of mc to make sure fluid returns? I was thinking about using some clear hose to a baby food jar but did figure it would move enough fluid to tell if what was going in was going back.

David