47re air check

I just put a 47re together. When I apply air to direct clutch I get a thump but also some hissing. I pulled a core off the shelf and get the same exact thing (thump with hissing). I changed seal on drum and piston, didn't see any cracks changed piston no change. Put another drum in with new seals and same deal. Any ideas?

how much pressure are you using to test?

120 or so

According to the build team at Firepunk, it should vent some when tested at 120. As long as the seal lip is okay, you should be fine.

Thank you and the guys at Firepunk very much!!!