Small Minimag Leak

[Maffer]

Hi guys, I recently bought a minimag from a guy who hardly knew anything about automags, and wasn't any help at all so I'm hopeing someone here can help me. My minimag has a classic valve with a shocktech uprade regulator body. When I gas up the gun, there is a small leak out the back, from the best I can tell it comes out the reg nut. The gun also came with the regulat automag classic regulator body and I changed it with the shocktech one, and I get the same problem. Regulator seat is in perfect condition and I have read the manual and cannot figure out what is wrong... and help would be very much appreciated.

[Maffer]

I am also useing HPA, and I'm not sure if I have a HP piston assembaly. Anyone know how I could find out? thanks

[silentdeath55]

Welcome to AO! I had this same problem with my mag. The AIR valve has an integrated regulator and will vent out the back if the internal pressure is to high. You said you had a shocktech valve or something and I have never heard of that, but they probably have basically the same internal concepts, so that is most likely your problem. Try oiling all of your o-rings nad see if that helps at all. If not its probably just venting.

As for the piston, are you talking about the HPA tank, or the piston in the valve. If you talking about the one in the valve, you should be able to see it if you unscrew the valve from the reg body. Stuck in the valve should be a little metal thing with a spring on it, that is the reg piston.

[Maffer]

Basicly the Shocktech regulator body I have is an aluminum 8 hole to allow more air flow. The piston I was talking about is on the gun itself, and I know it is there and works fine, but in the manual it says something about a HP piston assy. I have no idea what that is or if thats what I have.
As for the internals, yes they are exactly the same. How can you lower the internal pressure? All the o-rings are in perfect shape, I am out of oil, though they were oiled not long ago and I had the same problem then. Do guns always leak a little bit? I hope not because I have a 3000 psi tank and my gun is a gas HOG, which is one reason why I want to get this fixed, my friend with the RT valve doesn't use half the air I do. Thanks for helping, still isn't fixed tho :(

[AutomagRook]

if its leaking from the back, then its because your velocity is too high, try turning it down. turn the back part counter clockwise to turn down velocity. that should stop the leak.

[athomas]

Use the original automag regulator body. Make sure the inside of the regulator body is clean and free of any dirt. Make sure the regulator piston o-ring is in good shape. When you put it back together, make sure there is a slight bit of oil on the o-rings.

[dyeforever]

i had the same problem. what i did was replace the reg. piston with a high pressure one and haven't had a leak since. it hard to tell the difference between the stock one and the hp one. just replace it. it will save a lot of time and fustration.;)

[Marek]

If your using lvl. 10, then you need to get a new reg seat. If not, then oil it up and turn down the pressure.

[Maffer]

I don't have a lvl 10 and the velocity isn't too high, it's a SMALL leak... so right now I'm leaning towards dyeforevers suggestion, I probably need a high pressure piston. Anyone have any info on how much one would cost, and where I could get it at?

[xen_100]

there are only three reasons that you get a leak out the velocity adjuster nut.

1) bad reg piston o-ring
2) velocity set too high and causing the blow off valve to vent.
3) bad blow off valve.

if you said the reg piston o-ring is good, then it only leave one part. if the velocity is not turned up too high, then your blowoff valve has gone bad. replacing it with a new reg piston will fix the problem :)

BTW AGD only sells the high pressure reg piston. the only difference between the lowpressure one and the high pressure one is where the blow-off occurs. they are functionally the same thing. this was done to allow the level 10 to operate correctly (because it operates at a higher pressure than level did)

there never was a need to change to an "HPA" reg piston. the reg piston is what regulates the output pressure from the valve. so input pressure has NO effect on it. ( an technically co2 would have the posibility of a much higher input pressure than HPA would anyway, so this was not a real fix to anything)

[Maffer]

Thanks xen, that helped a lot... velocity is just fine except it jumps which I also atribute to the leak, and like I said the seat is brand new. Could you tell my what the reg piston is supposed to look like? If it's something fixable there's no sense in spending money on it :p
Thanks again for the help guys

[PyRo]

I think all the reg pistons look the same. Unless your reg piston has gone bad it shouldn't be leaking. You do know what turning the nut out is down for the velocity (some people have done that in the past, tippmann works there the opposite of the way mags work). Are you sure its not the airline comming into the valve? Reg pistons, spring packs, and on-offs rarley go bad.

[xen_100]

Originally posted by Maffer
Thanks xen, that helped a lot... velocity is just fine except it jumps which I also atribute to the leak, and like I said the seat is brand new. Could you tell my what the reg piston is supposed to look like? If it's something fixable there's no sense in spending money on it :p
Thanks again for the help guys

by "jumps" do you mean it goes up or down?

if the regpiston blowoff valve is the problem (which I think it is by now) buying a new one is the only solution. it cant be fixed.

http://store.airgun.com/acb/showdetl.cfm?&DID=17&Product_ID=48&CATID=6

[Maffer]

Yes, by jumping I meen the velocity is very erratic, sometimes 20 FPS jumps. By now I'm certain it's something to do with the regulator piston, or something in that general area... I just have no idea. Are there any tests I can do to narrow down what I'm looking for?

[xen_100]

I think you have done most of the tests. you just need to replace something and see if it fixes it. like I said, if the regpiston o-ring is good (and you have replaced it) then the only other reason it would leak out the back is the blow off valve.

there are only two reasons the blow off valve will leak:

1) velocity too high, turn it down and see if it goes away,

2) blow off valve is bad.

there is one other posibilty, if the reg seat was leaking, it would not regulate and it would make the blowoff valve vent. you said you replaced it, so it is not likely that. ( and ussualy a leak reg seat will show itself as a creeping increase in velocity that is normal when fired a couple times, but high after you wait a while you will get one hot shot.)

any way you look at it, you will have to replace something to eliminate it as the problem. a regpsiton is only $12, so at least it is not a spendy fix.

[Maffer]

:) Thank you Xen, you've been very helpful. I thank you for the time that you've spent trying to fix my poor gun, looks like I gotta give in and head to the shop (too bad it's a half hour away :rolleyes: )
Anyway, thanks again to all that sent in help for me!