Rebuilding Minimag (Old Timer)

[greystone]

Back when I played, (~15 years ago) anything AGD was top dog. I kept my Minimag all these years. A month ago at a company outing, we played paintball, now I have the bug again. Got my old mag out of storage and I'd like to get it ready for play again. Here's the unfortunate part....

I live in Arizona, the dry climate in storage has dried out the mag. I've already bought a parts kit and lube, I'm getting ready to disassemble and replace all seals, and re-lube.

It's a Left handed Power Feed Minimag. Is this rare at all? Most I see are right side feeds...

1.) I have a Reactor valve in my mag..does this take the standard AGD o-rings that came in my parts kit?

2.) I had a power tube spacer kit, but I have no clue where the spacers besides the one already in the marker went.

3.)The regulator was also drilled out (8 hole I think?) by Smart Parts. I think I had a trigger job done at the same time.

4.) I got suckered by Smart Parts years ago and sent my mag in to have the Magic Box mod done, but I removed the Magic Box and plugged the hole before I put it into storage. I've lost the parts for the Magic Box.

How is this going to affect things? I ran CO2 back in the day, but I'll be purchasing HPA before I play again. I plan on removing the vertical ASA/expansion chamber and throwing a fore grip there. Can I run directly from the HPA tank into the reg? What kind of HPA tank should I be looking for?

Before I put it in storage, I remember having EXTREME shoot-down issues. Will rebuild/lubing the sucker fix these problems? While I have it torn down, what else should I look for? I no longer have an an air source, so I can't air it up to test it until I buy an HPA setup.

Thank you for any help you can offer.

[georgeyew]

Before you replace any orings, I would run a generous amount of oil through the marker to see if it leaks. You may be surprised by how the mag can come back to life.

The spacers go in the power tube. But the current spacer that you have in there may be sufficient (they don't wear out).

The 8 hole mod should not be an issue. And as long as you plugged up the hole for the magic box, the valve should be just fine.

When you get HPA, make sure to get the high pressure version (>800 psi). But you'll be able to run that straight to the valve. Any name brand tank should be fine. The popular one right now is from Ninja.

Hope this helps you out.

[DeuceSV]

I live in Tucson, how about you? I would be more than happy to take a look at what you've got, but my guess is you will not need much work to get it running. the foregrip is a good idea, I actually have a spare ANS foregrip with steel hosing attached to an asa that could mount to the bottom of your frame if you're interested, I'll just send it to you as a holiday gift. Once its on there, all you need is to screw the tank in and go!

Send me a PM and we can discuss. As for an HPA tank, what fields will you normally be playing at? Most fields in Phoenix fill both 3000 and 4500 tanks, but of the two fields in Tucson, one only fills 3000 tanks. Either tank should prove to be fine, just make sure that when you buy it, the seller makes sure you get a tank with a high pressure output. The average CROSSFIRE tank with a high pressure output regulator will be perfect for your mag.

Welcome Back to The Addiction,
Jason

:cheers:

[Coralis]

The reactor valve you have will take the orings that come in the parts kit , however i would consider getting a new on/off as those reactors where a pain in the rump.

The shoot down issues were probably caused by CO2, mags shoot much better on HPA than CO2 unless you go to major pains to set the gun up for CO2 ( like anti-siphon bottles, expansion chambers , remotes etc etc)

[SkinnyHare]

greystone, check your private messages when you get a chance.

[greystone]

The reactor valve you have will take the orings that come in the parts kit , however i would consider getting a new on/off as those reactors where a pain in the rump.

The shoot down issues were probably caused by CO2, mags shoot much better on HPA than CO2 unless you go to major pains to set the gun up for CO2 ( like anti-siphon bottles, expansion chambers , remotes etc etc)

If the Reactor valve is junk, have any recommendations on what to replace it with? My stock valve is long gone...

[classic68]

You will like HPA much better then CO2. It is much more consistent. I used to play up north and the mag hated CO2 and cold weather. I live in the south now. I swap back and forth depending on where I am playing (HPA available or not). That is the great thing about the older mags. They can use either.

[Coralis]

If the Reactor valve is junk, have any recommendations on what to replace it with? My stock valve is long gone...

Im not saying its junk but I got tired of looking for the disk that tends to fall out every time you pull the valve out to do any cleaning , but to answer your question http://store.airgundesignsusa.com/index.cfm?fuseaction=catalog.prodInfo&productID=202&categoryID=18

[athomas]

Replace all your orings to start. That way you are eliminating any potential problems due to hardened orings. Shootdown can be caused by worn regulator seat oring or even a weak bolt spring causing a slow bolt return. While the reactor on-off is more of a pain than a standard on-off, it should be fine with fresh new orings.

[greystone]

All 0-rings have been replaced, from the barrel o-rings to the o-ring inside of the regulator.

But here's a question. I ordered an Air America "Quick Rebuild" kit that is supposed to have parts for my regulator. The appropriate o-rings were included for the regulator, but it also came with a new spring and regulalator valve pin. The spring is the same size as my stock spring, but the new regulator valve pin is slightly longer and has a conical shape rather that a plateau like my stock one does. Is this an upgrade or improved design? I double checked the part number of the kit, and it certainly is the correct one.

For example:

Stock Pin: ##]-----

New Pin: ##>------

[athomas]

I never use any orings that are not AGD unless I hand select the individual orings from a known brand myself. They don't seem to be the same quality from other manufacturers.

The Air America regulators may use the same orings as the AGD regulator, but the pin is probably different and the regulator spring may not be the same. They may work, but I don't know for sure.

[greystone]

I never use any orings that are not AGD unless I hand select the individual orings from a known brand myself. They don't seem to be the same quality from other manufacturers.

The Air America regulators may use the same orings as the AGD regulator, but the pin is probably different and the regulator spring may not be the same. They may work, but I don't know for sure.


I used the regulator o-rings from the AGD kit, I didnt use anything from the AA kit after I discovered the differences in the regulator valve pin.

[greystone]

Had plans on playing tomorrow morning, until I tried to gas up the minimag today...

I replaced every o-ring and seal in the entire marker, replaced the bolt spring, lubed everything with autolube. Prior to me doing this, the mag hasn't been gassed up in 10+ years.

After gassing up the marker.

I have a serious leak in the back half of the valve. So bad that in the short time it took me to turn off my on/off, my tank went from 3000psi to 2000psi.

At first, it was gushing directly out of the back allen key hole. I assumed I had accidently increased velocity too much, so I de-gassed the marker, turned down the velocity and gassed it back up. The leak was not nearly as bad, so I tried turning velocity up and down with no marked results. After taking everything apart, checking to make sure every o-ring was seated and lubed, I put it back together and had the same problem. Before I blew through all the air in my tank that was just filled, I noticed that it also seemed to be leaking from the back half of the rail area.

I remember 10+ years ago that the very last time I played I had a small leak out of the velocity adjustment hole...but I haven't played since so the thought hadn't crossed my mind.

Any suggestions? Buying a new valve isn't in my means at the moment.

[maniacmechanic]

I think this is what your going thru


http://www.automags.org/forums/showthread.php?t=248105

[athomas]

It sounds like you are getting sever overpressure. Did you make sure to put the regulator seat oring in so that the wider end snapped into the holder on the front of the valve back? It won't seal properly if it is on backwards.

[greystone]

I think this is what your going thru


http://www.automags.org/forums/showthread.php?t=248105

I tried the suggestion in this thread, the seal was worn. It had a circular mark as described. I flipped it over, re-assembled, still have the same problem.

I checked the tank on 3 other guns to make sure the reg on the tank wasn't dumping some insane pressure....two autocockers and a sterling pump. No issues.

[greystone]

It sounds like you are getting sever overpressure. Did you make sure to put the regulator seat oring in so that the wider end snapped into the holder on the front of the valve back? It won't seal properly if it is on backwards.

Yes. The larger side is snapped into the reg.

[athomas]

When you changed the orings, did you do a complete wipe down of the parts in the valve and reg area with a clean cloth? Perhaps a piece of dirt got caught in the oring on the regulator piston assembly.

[flyingpootang]

It may be a piston o-ring. Degas your marker, remove your velocity screw, remove the spring pack, then the piston, Examine the o-ring around the piston for tears. When installing/inserting new o-rings it's better to lube them to prevent tearing...

[greystone]

Update....

Here's an odd thing. Out of pure frustration I've been swapping around O-rings to see if maybe I accidentally screwed one up while installing. Every O-ring looks fine by visual inspection, no marks or damage. I notice I was getting leak from between the valve and the regulator also, so I put back on my original, 10 year old large regulator O-ring, and the leak from around the reg stopped!

No leaks, I was able to dry-fire the marker until I ran out of air

The trigger pull was extremely hard.

I sit back down at my desk, and notice that the regulator valve spring and pin were sitting on my desk...I didnt re-install them. So apparently I no leak issues when the regulator valve spring and pin is missing...but they are both brand new.

???

[DeuceSV]

How interesting..

[Coralis]

perhaps you have rust or debris in the hole where the regulator pin and spring goes causing some over pressure problems , you could try cleaning it out with Q tip.

[secretweaponevan]

Be sure to thank TK that he designed the reg to withstand 3000 psi.

Interesting that your reg piston didn't overpressure-relieve though. I recommend looking at your reg piston for the malfunction.

[athomas]

That should have definately over-pressured the regulator piston assembly, given that you were putting 850psi directly into the chamber. There is a malfunction inside your regulator piston assembly.