Classic Mag, Classic problem

[TheDuelist]

I have an old level 7 former Smart Mag without the Magic Box installed. It recently developed a leak down the barrel. When i gas it up and pull the trigger the leak stops. I have had this problem before and fixed it but that was a couple of years ago and I have since gone from a mag to a matrix and now back to a mag and some things have gone with age. I would appreciate the help in getting it up and running again. The setup is as follows:

Classic Valve, HPA (input is 800 psi I believe, benchmark frame, stock bolt

I have replaced the o rings inside the marker but I am obviously missing something. Any help is greatly appreciated.

[Magaholic]

power tube oring

Check your power tube oring. A leak down the barrel that stops with the trigger pulled is a sign that your power tube oring could be bad.

[TheDuelist]

Well I tried a different search than my first one and I think I might have found a solution so i'll try it. I don't recall there being a spacer in the PT and if there is I don't know what size it is so i'll try and change it out and see if it cures my problem. Its amazing what a properly written search will do.

[Nobody077]

If your level 7 valve is old enough you may still have a powertube spring. If you do then either upgrade to the spacer kit or jump to level 10, but first check your powertube o-ring. If you plan on putting LX in your gun then skip the spacer kit beacuse you dont use them with LX

[athomas]

Check the powertube o-ring and spacer/spring. The older smart mags did have powertube springs. Replace the spring or put a spacer kit in with the proper spacer. That should stop the leaking.