I haven’t seen this on the forums so I thought I’d share. Utah Airguns has a video on rebuilding the FX AMP Regulator. After you get that troublesome o ring out the hole, and the holes is cleaned out, put in the piston with enough belleville washers to reach the bottom of the o ring groove. It takes a few seconds to put the new o ring in using the washer stack to push against. Have a nice day.
