AT44 QE pressure tube leaking

[Mikeflys]

I went to do a little plinking this morning. First shot sounded funny, checked the gage. It was way down. I thought that was odd I didn't remember putting it away like that, and I don't normally shoot it down that low. Took it back inside and pumped it up to 200 Bar. Once I removed the fill probe, I can hear hissing. It is coming from the fill port end. I released all the pressure and am attempting to remove the gauge end of the tube. It is understandably really tight. Is it safe to use a screwdriver through the fill port for leverage? Am I in for any surprises when I remove that cap? I am hoping the O-ring kit that came with the rifle will have the needed replacments. 

[Madd Hatter]

I've never worked on a at44 but I used a round #3 screw driver to unscrew the end cap of my liberty to repair the check valve. The shaft of the screw driver was almost the same size as the probe hole in the end cap.

[Back_Roads]

 Yup  #3 round screwdriver shaft in the fill port hole might need a rubber jaw vice or strap wrench to hold the tube, first time off can be a bugger sometimes.