Minimag help!!

[TippmannFireman]

I'm about ready to shoot myself. My Minimag WILL NOT WORK NO MATTER WHAT I DO! It leaks, then it won't shoot, I need a complete guide on how to rebuild a Minimag valve from the bottom up. I'm furious right now cause this stupid thing won't work. :cuss: :cuss:

[MAGpie]

I'm about ready to shoot myself. My Minimag WILL NOT WORK NO MATTER WHAT I DO! It leaks, then it won't shoot, I need a complete guide on how to rebuild a Minimag valve from the bottom up. I'm furious right now cause this stupid thing won't work. :cuss: :cuss:

http://www.airgundesignsusa.com/Images/automan.pdf?bcsi_scan_8FEF85425364CA44=0&bcsi_scan_filename=automan.pdf

;)

[TippmannFireman]

Saw that a few minutes ago.. Let me explain what's going on and maybe I someone can help with it.

I air the gun up, and it leaks out the ASA. Fair enough. I just got the ASA used, and it needed an o-ring. I can deal with that. So I take the expansion chamber and ASA off, and just screw the tank into the vertical ASA, and it starts BLOWING out of the barrel. So I take it apart, make sure everything looks okay, and figure I'll air it up again. I screw the tank in again, and it leaks a little bit, so I shoot it, and it fires 3 REALLY REALLY REALLY fast shots, so I shoot it again, and it fires again, and then starts leaking like crap again. So I degas it, take the valve out, and just because I'm stupid, I air it up without being in the body. Well, what I'm assuming is the on/off valve thing flys out and hits me in the hand. Fair enough. So I look at it, and one of the o-rings is off of it. So I put it back on, put it back in it's hole, and air it up again, and it does the same thing. It will not work right, it leaks, I'm just upset with it.

So, NOW what do you think?

[Jacobd]

Sounds like you should start by replacing the powertube oring and on-off orings. There should be 4 orings in the on-off, two little white ones and two larger tan ones. After you do that make sure it's back together how it says on the valve, squirt some oil into the valve, turn the velocity down a good bit and see what you've got.

[factoid]

Does holding down the trigger stop your leak? If so the leak is in your powertube. If it has a level 10 bolt, put in a smaller carrier. They're marked with lines and dots. A line is 1 and a dot it .5 so if you've got a carrier with one line and one dot it's a 1.5 carrier.

Assume you have some, try a carrier with a smaller marking on it.

If you've got any silver shims in there take them out. Try using a fresh o-ring for both the white and black o-rings on the carrier.


If you've got a level 7 bolt you should try a new powertube o-ring first. If you have a spring inside the power tube it might be worn out and need to be replaced.

Check your bolt spring as well. It should be longer than the end of the bolt. If it's compressed to the point that it sits flush with the bolt face (or even farther back) it's worn out and should be replaced.

If you have a spring inside your powertube, I'd recommend either just upgrading to a level 10 bolt, or if you don't want to spend that much at least buy the powertube spacer kit. They're better than the springs.

[TippmannFireman]

Here's what I found when I took the on/off thing out. The bolt spring it flush with the end of the bolt. The power tube o-ring looks good.

This is how the on/off thing came out.

http://img40.imageshack.us/img40/6421/p1140251d.jpg (http://img40.imageshack.us/i/p1140251d.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

I have a feeling something is wrong there.....

http://img233.imageshack.us/img233/6718/p1140252.jpg (http://img233.imageshack.us/i/p1140252.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

http://img251.imageshack.us/img251/1487/p1140253.jpg (http://img251.imageshack.us/i/p1140253.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

http://img259.imageshack.us/img259/9254/p1140254.jpg (http://img259.imageshack.us/i/p1140254.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

[theGOLDENchild]

At first glance, you're missing half an oring. Your bolt spring should also be replaced, it should extend past the bolt to work correctly.

[factoid]

Yep, your teflon o-ring is toast. It's supposed to be solid, not split in half like that. I can see how that causes intermittent leaking. It probably seals up OK most of the time, but the vibration from shooting is occassionally causing it to create a gap.

Your other o-rings look like they might need to be replaced as well. If you have a rebuild kit you should replace all 4 on/off o-rings with new ones. If the rebuild kit you're using is old, buy a new one.

Your urethane o-rings (the two big ones) look a little brown. This was normal for some off-brand o-rings and for o-rings that are getting old. A new one should be almost a milky white color, maybe just slightly tan.

The white teflon o-rings should be small, hard and smooth. No raised edges or bumps.

The best way to assemble a classic on/off is as follows:

Start with an bare on/off top (the silver piece). Take all the o-rings out. Any new o-rings that you put in, give them a light coat of oil...just a drop or two on your fingers and rub it around. Put on a fresh urethane o-ring into the groove on the outside. Put a white teflon o-ring into the small cavity on one end.

Insert the on/off pin while holding it by the little nub. Insert it through the small hole in the on/off bottom. This is very important...it looks like in your picture you might have your on/off pin upside down. The smooth end is what goes in contact with the o-rings, NOT the notched end.

Now that the pin is in, put the brass on/off top on the pin and put the white teflon o-ring over that to hold it in place.

Make sure the whole where you on/off assembly fits into the valve is empty. If there are any o-rings in there take them out. Put a fresh one of the larger urethane o-rings into it.

Now you've got one o-ring inside your valve and three on your on/off. The on/off should slip into the hole and you'll feel the white teflon o-ring slip inside the urethane o-ring (that sounded really dirty reading it back in my head). It's OK if the assembly pops back out a bit. As soon as you put pressure in the valve it should seat itself.


Now more oil. You should oil every o-ring lightly before putting it in, but mags can't have too much oil, so put three or four drops of light synthetic oil into the ASA before you screw your tank on. Don't use gun oil or sewing machine oil...get auto lube, gold cup or some sort of air tool oil from the hardware store.

Dry fire the gun 20-30 times without the barrel on. Most of that oil is going to blow right back out the gun so you don't want it coating your barrel and making your paintballs do corkscrews. I personally like to remove my valve after dry firing it and wiping down the breech and bolt to get the excess oil off those as well.

That was a pretty long winded explanation...but hopefully it helps. When it doubt make sure you check out the little laser engraved diagram on the side of your valve. It shows the correct ordering of all the on/off pieces.

[TippmannFireman]

You are the man! Where would I go about getting a new spring and a rebuild kit? How much is it going to cost me? Can't thank you enough for typing that out for me.

EDIT:

Something like this?

http://cgi.ebay.com/AUTOMAG-Classic-Minimag-68-Automag-O-RING-KIT-/200529748499?pt=LH_DefaultDomain_0&hash=item2eb0812213#ht_1684wt_932

And this?

http://cgi.ebay.com/AUTOMAG-MINIMAG-MAG-PAINTBALL-GUN-Main-Bolt-Spring-AGD-/400016902501?pt=LH_DefaultDomain_0&hash=item5d22dd8965#ht_500wt_715

[theGOLDENchild]

A new bolt spring should come with the rebuild kit. You can get the kit from Tunaman (tunamart.com), Airgun Designs, and from pbgear.com. I would recommend Tuna.

[TippmannFireman]

Like so?

http://www.tunamart.com/index.php?c=46&p=7

[factoid]

Like so?

http://www.tunamart.com/index.php?c=46&p=7

That's the one you want. I've also bought direct from AGD and from Action Village before...same parts kit. It's got enough o-rings for two full rebuilds on just about all of the parts except for a few that rarely if ever go bad, like the reg body o-ring.

Make sure you get the reg piston o-ring as well. Lots of people forget about that because it's buried deep in the regulator. Take the velocity nut all the way off, pull out the spring pack and the piston sits underneath.

The on/off o-rings are the most finicky. Everything else goes in pretty easily, especially if you've got a dental pick...that's an excellent 5 dollar investment for your mag, or any paintball marker really.

[TippmannFireman]

Where might I pick up a dental pick?

[factoid]

Where might I pick up a dental pick?


Medical supply stores usually have them. Craft and hobby stores usually have picks made for working with clay...those would work too. You need something that's not super flimsy though. Some dental picks are very fine tipped, you want one that tapers a bit to be come thicker so you can apply force to it without bending it.

i can't honestly remember where I got mine, it's been in my tool kit for so long.

I have a set of woodworking picks that are quite a bit bigger but would probably still be OK for working on paintball equipment. I got those at a hardware store.

[cyberave68]

Where might I pick up a dental pick?


Local auto parts store or Ebay...

[TippmannFireman]

Why would an auto parts store have a dental pick?

[factoid]

Why would an auto parts store have a dental pick?

It's probably not a "dental" pick, but they probably have similar kinds of picks because they're useful for working in small spaces, cleaning gears, separating wires, etc...

[cyberave68]

Why would an auto parts store have a dental pick?
they dont call them dental picks. They call them O-ring picks...

http://www.autozone.com/autozone/accessories/Tools-Garage-and-Equipment/O-Ring-Pick-Tool/_/N-26f5?filterByKeyWord=o-ring&fromString=search

[TippmannFireman]

Oh! Right. Heh, I knew that. :rofl:

[aerosaaber]

I got a set of picks at harbor freight for like $2 (4 different styles)

[TippmannFireman]

Awesome! May ride out there in the morning, then.