My first foray into pneumatic retracts. I had a spool valve that would leak air under pressure, it would lose 80 psi in 5 - 10 min. It was from Black Horse, as the construction was nearly identical to the fixed gear from Seagull that came with the plane (82" AT-6). I bought a new one, a Robart, and it will lose air, but about 5 psi in an hour. I think that's good, but I haven't found anything to tell me what I should be looking for as far as what constitutes good or bad. Once I hook the lines to the retracts themselves, I know I will get more leakage, but what kind of loss over what time would be acceptable? Say I start with 100 psi in the tank, should I have maybe more than 50 psi left after an hour, or should I cycle the gear say, 4 times in the hour, and have 30 psi left?