[cook_dw]

I literally just finished doing the same thing on the green L78 car last night.. I had an issue with the metering valve at the beginning as it was leaking along with the master. After replacing the master with another WT mc (father put discs on it back in the 80s) I rebuilt and reinstalled the metering valve I couldnt get a good pedal and realized it was leaking fluid out past the rear seal.. Pulled it back apart and there was a very small chunk of rust down in the crevice were the seal seats. Got in there with a pick and cleaned it out and I now rock hard pedal. Not sure itll be your problem but was the answer for me.. As far a bench test of the parts... When I pulled the metering valve apart it was frozen together and you could tell it wasnt working properly.. Not sure about the distribution block. Also do you have a proportioning valve down on the frame? Also might look at the wheel cylinders making sure they are leaking or bleeding off. Just some thoughts.