Leaky reg...

[Watcher]

A big damper on this weekends gameplay at LivingLegends5, my mag was giving me grief.

First my warp-feed's motor burns out (I think, it stopped spinning shortly after changing the batteries before I even got to play with it. Fiddled with it for a while, tried touching a 9v to the terminals of the motor and it didn't spin. Joy...), but lucky for me I was with someone who had a spare I could use.


But, my biggest grief was that after chronoing, walking to my insertion, breaking contact, and firing a small burst my RTPro valve starts leaking out of the back of the reg through the adjustment hole.

It wasn't serious enough to dump the tank, but it was an audible hiss that was bothering me while I had it in my hands. As soon as I got shot out, I found someone in the staging area with oil and flooded my ASA with it. It had the effect of making the leak WORSE!

So I hiked back to my truck for my parts/tools and over to my tent to tech it. Took the reg apart, took out the piston, and the o-ring on the tip was all stiff and discolored.
After hunting around in various parts kits I find the correct o-ring, install it, and lube it up.

Get it back on air, get it shooting, go chrono, get it up to velocity, then "hissssssssssss".
It didn't bother me enough not to play with it, and the RTPro performed admirably the rest of the day, but it is still an issue and probably why I can't get the trigger to respond anymore.


I did experience the same leak in this mag before, with my old RT Classic when I used to have one, and some mags that I've worked on at my shop, and every time the piston o-ring always solved the problem. Could it be anything else?

[Ando]

Could be, ck your oring again. Clean out the cavity, could be some grit in there keeping it from sealing.

[Watcher]

That I will do at work tomorrow.

Any chance switching from a urethane o-ring (yellow/clear/white) to a buna o-ring (black) would be better/worse?

I am currently out of the AGD spec urethane ones but I have drawers full of the buna o-rings in various sizes. I have used them in on/offs and powertubes with recurring success.

[Ando]

It should work. They don't last years and years but will work.

[Watcher]

It should work. They don't last years and years but will work.

Cool. Hey, with proper lubrication they'll last. I keep my RT so oiled up some of the O-rings I installed back when I got the gun in 2008 still look new! I've seen too many that old turn brown...

Not sure why my reg o-ring went when the rest are almost perfect. I might never know...

[athomas]

Urethane is used in mags because it has better wear properties. The buna oring will last if you keep it wet but because its an oring that is subject to movement for every shot, it will wear faster than urethane. Most of the orings in a mag have some movement associated with them, which is why all the orings in the mag are urethane.

That particular oring might have gone bad quicker than others because it is subject to a lot of movement and does not see as much continuous lubrication. All other orings in the valve are in the air flow path and have oil flowing past them when you put it in the ASA or intake. If you want to lubricate the outside of the oring for the reg assembly, put some oil in the rear side hole.

[Watcher]

Well, it seems my shop is out of the correct size o-ring and will be a while before we get more, so I guess I have to order from AGD.

Cool, I could use some new parts besides o-rings anyway, I just don't like waiting