but how do you KNOW its not leaking?
TurboXS valves in general work very well. Just gotta use the right amount of washers for your particular car.
Oddly enough, the normal type-H seems to work a little better than the RFL. I cant for the life of me see ANY reason whatsoever for this, they are identical other than the horn on the RFL. But the 3 RFLs I tested had to have an additional washer to hold the same as the normal type-H.