The round foam energizer ring that comes with servo rebuild kit is a little too large in diameter or the durometer is greater than original. In any case it puts too much pressure on the leather seal and the piston will not retract once vacuum is reapplied to the head side thru the air chest "Tee" valve. I was a little skeptical that the problem was that simple but went ahead and removed the energizer ring per Bobs recommendation. Worked like a dream. Brake lock is a thing of the past! Horray for the power of networking thru the Alpine listing!
Bob Flak