Tuning Maximus leaking air

[Hummer57]

Out of the blue, my Maximus is leaking air. Got it down to shoot yesterday and noticed it had no air pressure. Filled it and shot six rounds on the chrony. 805 FPS avg.. Refilled it and this morning it’s empty again. No mods except trigger replacement. Any ideas or suggestions?

 

[rong1966]

Take it out of the stock, fill it up and spray a dish soap water solution at the fill area and at the pressure gauge area. My maximus leaked twice at the gauge block; I replaced it the first time and replaced the two o rings the second time. Mine also leaked at the fill nipple; I had to replace the whole fill piece because I could not remove the male foster by itself. Check these areas first, but it could also leak at the valve.

 

[Hummer57]

I’ll do that today. Thanks 

 

[MJS]

My Maximus leaked at the fill adapter after about 3.5 yrs. Crosman sent me a replacement for free. No problems since. Here's the part #:

 

[MMCM13]

Same as above with mine, first thing to leak was the fill connection.

 

[Hummer57]

No leak at the fill port or pressure gauge area.

 

[Ripper]

 I’ve had one for over three years with no leaks yet luckily. If it’s not leaking in those two areas, you might want to check to see if it’s leaking at the valve which hopefully it isn’t. You put a balloon on the end of the barrel and make sure it fits tight and let it sit Overnight and if it is leaking, it will fill the balloon up.

 

[Hummer57]

Update: After filling it today to check for leaks, I left it in the living area of my cabin. It hasn’t leaked at all. I keep several PCP’s in the back room (man cave) of the cabin. The average temp back there is 40F. That must be too cold. My Bantam sniper was also low on air. I filled it and shot it then put it the living area to see if that makes a difference. Maybe it’s just temp related. I’ll update tomorrow.