The last two times I filled my Maximus it keeps bleeding air from the gun when I open the release valve on my Hill pump. After I close it off and pump up again it works properly. Is it the gun or the pump? Thanks in advance for help!
Tuning Back pressure leak
- Thread starter Kenmc
- Start date
Sounds like the check valve in the Foster fitting is beginning to fail...the gun, not the pump. Often times when the O-ring is beginning to go, it will seal intermittently or have a slow leak before it goes out completely. Generally Crosman uses a -006 size. Good ole Buna-N in 70 or 90 durometer will do nicely.
Upvote 0
Thanks! Wow, the gun is only about 2 months old. Not very promising. I am beginning to have 2nd thoughts about PCP’s.
Upvote 0
Sounds like you bleeding the line too slow. Get a move on don't dilly dally unscrew the bleeder Screw as quick as possible.
Upvote 0
If it still does it after hurrying up unscrewing the bleeder next time have a rubber mallet whack the front close to the end by filler hose while bleeding and line still connected with a rubber mallet or your hand lije you beating it to death to force it to close the check valve to stop leaking.
Upvote 0
Hmmm, I can’t unplug it as long as it has pressure against the hose so I don’t understand how speed would have anything to do with it. It puzzles me how when I pump it back up after loosing the air attempting to bleed, it holds. And the gun doesn’t loose any air even after a few days.
Upvote 0
Thanks for that link! I will try that , hopefully today. So, if I cock it I will need to dry fire or fire it before storing right?
Upvote 0
No need to cock it or even shoot it before storage once it's already filled with air. Don't leave it cocked unless you are filling the gun from empty. Don't leave it cocked while stored.
Upvote 0
As per the link / I cocked before filling and had no issue today. I had forgotten it can be uncocked like a hammer type firearm.
Upvote 0