Can't refill after reg installation

Hi guys,

So I've just installed a huma reg on my air arms s510 .22 xtra FAC.
I know I've not made anything wrong during the process but the problem now is that I can't refill the rifle. I'm pumping like a bast**d, the pump shows 50 bars and I can't go higher as I can hear air leaking through the barrel.. I've tried cooked, uncocked.. Nothing changes, air keeps leaking.

Any suggestion please guys ?? =)
 
Try cocking the gun just so that there is no pressure on the valve during refilling from zero pressure. It's more difficult to fill the air tube with a hand pump when it is completely empty as the air just tends to escape. That's why when filling with a tank it's easier to do so as the initial blast of air from the SCUBA/SCBA tank dumps high-pressure air quickly, thus pressing against the valve and sealing it shut.