Air leak out the back of an RT valve

[temilotzin]

[nak81783]

Do you have a Level 10? If so, they sometimes require a higher pressure safety relief piston - #5 in picture. The older valves that had Level 7s don’t have the newer piston. Contact Tuna or AGD.

What bolt spring are you running? If gray or red, go down to gold for now. That will let you turn pressure down and achieve same velocity. If you must use gray or red, you’ll likely need the newer piston.

Is it leaking out the rear tiny side hole too, or just the back where you put the wrench to adjust velocity? If rear tiny side hole is leaking too, clean/re-oil/replace #6 as needed.

[temilotzin]

Level 10, I replaced the reg piston when I upgraded it to level 10, close to twenty years ago now. Do they go bad over time? Red spring. Just leaking out the back where the wrench goes.

[nak81783]

Apparently so. From AGD's website: Replace this part when air is venting out the back of the marker and you are shooting less than 300 FPS.

How badly is it leaking? Maybe try replacing #11 (reg seat) first. A bad reg seat would let excess pressure in, but the venting might "regulate" it such that it still shoots 285fps.

If you do end up ordering a new piston, perhaps try the gold spring. That might buy you time while the part ships to you.

[Tunaman]

Definately replace the reg pin orings and the reg seat oring before scrapping the reg piston...

[temilotzin]