This AIR valve has a Spring, not a PT spacer?

[JEDI]

I've got a classic Mag that my friend would like me to look at. It has an older AIR valve in it. He told me it leaks down the barrel, so I immediately thought, Power tube spacer. I opened the powertube, and found a little brass spring instead of a spacer.

Now, leaks down the barrel mean a smaller spacer is needed. So where do you start, when its a spring and not a spacer. How do I know what size spacer to recomend? Is there one or two average sizes I can tell him to get. I'd rather not say, "buy every size" Heres a pic.

[Ejp414]

mine too, it's just older, they replaced them with the spacers later. I'm not sure how you would fix the problem.

[guysdaman]

most likely it is the power tube o-ring, you can get a spacer kit from the store to replace the spring or you can do what I did and get the LVL 10 bolt...it is well worth the money...trust me and ask any mag user that has one!
Good luck

[JEDI]

Well, this isn't my Mag. I would suggest the LX as a complete fix, but I know this set up is what will have to work for now. Does any one know how to make "leak proof" adjustments with the spring? Or can some one suggest what to do with spacers. I have an LX Emag, so I've never dealt with the whole spacer issue. Thanks.

[athomas]

Check/replace the powertube o-ring. Check the sear for signs of wear that may cause the bolt to sit farther forward. It doesn't take much.


A spacer kit may help by allowing the powertube o-ring to sit farther forward.

[Gadget]

Leaks are usually just the power tube o-ring - if you replace that, lightly oil it and refit the spring (smoothest face against the o-ring) and tip, you should fix the leak. Check that the bumper isn't chewed up.

If you want to go with spacers instead, first fit a new power tube o-ring and then install the largest spacer. Test that, if it leaks take that spacer out and go for the next size down. Spacers just determine where the o-ring sits in the power tube - a large one keeps it near the bottom of the tube (meaning leaks are more likely as the bolt stem might not reach it) and smaller ones keep it near the top, meaning leaks are less likely but you might get bolt stick.

If you get bolt-stick it can be because the spacer is too short, allowing the o-ring to sit too far up the power tube and grip the bolt stem too much.

[JEDI]

Ok, so lemme get this straight. The power tube o-ring goes into the tube first, right? BUT, the spacer determines how far up the tube the O-ring sits? I thought the O-ring goes all the way in and stops. How does the spacer make any difference? Is it like the LX carriers, where now the O-ring sits in the spacer? Sorry for my confusion, but I really appreciate the help you guys are giving.

[Gadget]

Yep, you've got it right - the o-ring pushes all the way to the bottom, then the spacers sits on top of it....

BUT (and it took me a while to get this too) - when you gas up the marker, the o-ring actually gets pushed up the power tube by the pressure, the spacer then determines how far up it can get pushed before it stops.

[JEDI]

Thanks! Ok, with that understood, I'll try your advice. First try a new O-ring.

Bigger spacer = no bolt stick, possible leaks.
Smaller spacer = No leaks, possible bolt stick.
-To put it simply.
Thanks again.

[Lee]

my experience: .215 or .220 spacers are the most commonly used. can't hurt to change the o-ring either.

[xen_100]

just get a spacer kit, it has all the spacers you need. only $12.

[FlipShot]

Wow it must be really old, I bought mine in like '98 and it came with a .225 spacer.

[JEDI]

Thanks guys. I put a new power tube O-ring in and replaced the spring with a .220 spacer. No leaks. No stick. This gun is pretty darn fast for an AIR valve and a double trigger.