Classic mag regulator problems

[factoid]

Strange things happening to my mag today:

I was shooting consistently most of the day. My first shot at the chrono was maybe a little hot compared to following shots, but no where near as bad as it was last week before I cleaned up the reg piston, switched reg seats, etc...

At the end of the day I chopped a ball (need to get that level 10 upgrade) and all of a sudden I started noticing that my first shot was nice and strong, and the rest of the string was weak. It hadn't been like that all day, just that last game.

After the game I was showing my mag to some kids who had never seen one before and I field stripped it because I needed to clean the bolt anyway. I also screwed off the reg to show them how it tore down. I checked the reg seal while I was in there just to see if I had picked up some dirt or something. Didn't notice anything, but I gave it a thumb rubbing anyway.


After I got home I decided to gas up and see if I could re-create the issue while dry firing but I got a fast leak out of the back of the regulator. I tore it apart, cleaned off the regulator seat, the piston, etc... and put it back together and the leak went away. They hot-shot / shoot down problem wasn't happening while dry firing.

I'm wondering if I'm having some wierd problem with my regulator? Any thoughts?

[factoid]

Follow up question that probably has a more concrete answer:

How can one tell if their piston is a high pressure piston or not? Is there any visual difference? I see no markings on it to tell me.

My mag was new in 99/2000 and came originally set up for CO2.

I'm wondering whether I should buy the high pressure piston and/or possibly a new spring pack.

[Ando]

I would first try to clean out the inside of the reg. Replace the packing on the piston, even the reg seat then try it again before you go spend anything on it.

Usually a leak out the back means you have your velocity up too high but if that's not the case then a good cleaning and packing replacement should hopefully fix it.

[factoid]

I would first try to clean out the inside of the reg. Replace the packing on the piston, even the reg seat then try it again before you go spend anything on it.

Usually a leak out the back means you have your velocity up too high but if that's not the case then a good cleaning and packing replacement should hopefully fix it.


I know it's not a velocity issue because I didn't adjust it at all between the field and home. I was thinking I might have introduced some dirt into it when I field stripped it outdoors.


When you say "replaced the packing on the piston" what does that mean? Do you mean remove the old grease and put it on fresh? Or are you refering to an actual part of the piston?

I am inclined to think my reg seats are fine. The two I've tried are brand new, so unless it was a bad batch they shouldn't be the problem.

[Ando]

If your sure it's not a velocity issue then only other thing it could be is the packing on the brass piston or the piston itself.

[factoid]

I gave it a light coating of oil when I tore it down. The leaking stopped after that and it seems to dry fire consistently, but I can't run any paint through it to check.

I really need to get myself a handfull of re-balls that I can shoot into a pillow or something.

[questionful]

I bet it's the reg seat.
http://www.youtube.com/watch?v=7C_1nufgDmU
http://www.automags.org/forums/showthread.php?s=&threadid=7291

btw i think you're supposed to lube the reg piston with lithium grease.

i would say inspect the reg seat and reg piston o-ring.

[factoid]

I bet it's the reg seat.
http://www.youtube.com/watch?v=7C_1nufgDmU
http://www.automags.org/forums/showthread.php?s=&threadid=7291

btw i think you're supposed to lube the reg piston with lithium grease.

i would say inspect the reg seat and reg piston o-ring.

I have to pick up some different types of grease anyway, so I'll grab a small tube of lithium while I'm at it.

I don't see how it can be the reg seat though. It's brand new. I put it in about 4 days ago and saturday was the first game I played with it. Unless a really microscopic piece of dirt got in there and can cause a huge leak like that. Or the two reg seats in my rebuilt kit were from a bad batch.

[athomas]

No, do not lube the piston with grease. It will gum it up and cause problems. The only lubricant on any moving part should be a light oil. The grease is only meant for the springs, to keep moisture from causing rust.

The fast leak when you go home was probably due to the regulator seat leaking after you had it apart at the field. A leak at the reg seat would cause an overpressure situtation which would be vented out the back by the regulator piston assembly. Unless you are using a level 10 bolt, you won't need a new piston.

There is a real possibility that rubbing the seat with your fingers cleaned whatever tiny piece of debris away that was causing your leak. Another thing you might want to do, is inspect the sealing surfaces that make contact with the seat. That would be the back half of the valve and the regulator valve pin. If there is a blemish in the sealing surface, it could cause a problem.

[Spider-TW]

Hot shots occur when the reg seat trickles by, adding extra air over seconds. Shoot down occurs when the first shot is good, but the following shots of less than a second or so in between start to drop. Shoot down can pop up if something gets between the on/off pin and the sear, or the sear pin is not sitting all the way down in slot in the rail.

Also, old mags can have some shoot down if the hole in the regulator back is not lined up with the hole in the valve. But yours is a "Classic" isn't it? "Classics" should be lined up.

Once you get things working, you generally want to leave the reg alone unless you see a lot of blow thru grime from dirty air around the bolt.

[factoid]

Wow, more air problems!

I finally, after two weeks of searching, found someone who had Macroline elbows in stock. So I went about the task of replacing my old microline thinking that it might help aleviate some of my shoot down problems if that's what the problem was...the valve should be able to recharge much faster now with the increased flow.

I also cut my foregrip/expansion chamber out of the mix and went direct from my ASA to the valve

I put it all back together and found a leak, which I eventually traced to the on/off. I've never had a fast leak like that from the on/off before.

I pulled the valve assembly out and noticed that the teflon o-ring wasn't seated inside the urethane. THis always happens to me when I install new o-rings, but usually they will snap together after I gas up the marker once.

I didn't have much time to mess around with it so I just decided to swap both of those o-rings out and now it holds air just fine.


I'm really kind of disappointed with this parts kit. I've had problems with the reg seat and now with the on/off o-rings.

I'm hoping that the o-rings are actually fine and they just got wiggled loose or maybe I've got loose dirt flowing through the gun that's gone from screwing up my regulator to screwing up my on/off.

On the plus side I've now got the macroline on there, it's holding air, and it seems to be shooting pretty well. I even found a new detent for my cocker barrel adapter to replace the one I dropped and lost. Not technically a spyder detent, but very similar and it fits and it only cost me 25 cents. I'm gonna go back and buy about 5 more now :)

Anyone have any idea what could be causing all these weird air issues though? Is it connected or just a string of random coincidences? I've never had this much trouble with my mag in such a short period of time, but then again it's 11 years old now and I've been doing a lot of upgrades.

[Ando]

Is it an AGD parts kit from AGD themselves or some off brand?

[factoid]

Is it an AGD parts kit from AGD themselves or some off brand?

It's an AGD parts kit via ActionVillage.com

[Tunaman]

Like the Flatline reg, the classic valve should NOT be taken apart after installing a new reg seat. Leave it together until you have issues...which should be quite a long time. The sealing edges on the valve halves groove the reg seat, and it is impossible for them to line up correctly after you take it apart.

[factoid]

Thanks for the tip. I won't be opening it up again for some time, I don't think. I'd never seen anything that said you should basically replace your reg seal every time you crack the valve open. Actually I think in the maintenance video doesn't TK suggest cleaning it off with your thumb every so often?

It makes total sense, though and I'll refrain from cracking it open again unless absolutely necessary.