Is my sear worn out? (leaking)

[kjjm4]

I bought a PTP micromag recently. It has a minimag valve though (judging by the serial number MM022XX, it's really old, and it has no stars). When I got it, it leaked out the barrel, so I bought a rebuild kit, and replaced all the o rings, the reg seat, etc. It still leaks out the barrel. The leak stops when I hold the trigger all the way back. I have a power tube spacer kit, and I've tried the spacers from .215-.225. I didn't try the longer ones yet, but according to the directions that came with the kit, longer spacers are just likely to increase the leaking.

The top half of the on/off in my valve is not the same as the one in the exploded diagrams I've looked at either. It has crossed slots in it instead of holes. When I took it apart, there was no o-ring in the top half either. I couldn't find anywhere where it looked like an o-ring would go either.

What has me thinking that there is a problem with the sear is that the trigger seems easier to pull than it ought to be, and sometimes it will double or triple fire if I hold my finger right.

I oiled it and everything after I rebuilt it.

This is the first mag I've ever owned. I can't figure out how to fix the leak. Any help would be appreciated.

[Severe]

Judging from your description, I'm surprised it will stop leaking when you hold the trigger back. However, I might be misunderstanding you.

Are you saying that when you fire the marker and hold the trigger back it stops leaking?
OR
Are you saying that if you slightlye pull back on the trigger it stops leaking?

Either way, I would recommend you get a proper On/Off top. Heck, for $15.00 you can get a new complete On/Off assembly from AGD directly.

It'll be much easier to trouble shoot your leak once you have all stock components on the valve.

[kjjm4]

The leak stops when I fire the gun and hold the trigger to the rear.

It's leaking down the barrel. The powertube o ring is new; all the o rings are new.

[Severe]

Have you tried flipping over the On/Off top?

If I'm following your right your On/Off assembly should be like this:

Outer and inner o-rings placed in the body first.
Then place your On/Off Top in with the flat side to the o-rings.
Then place your On/Off Bottom in there with the all steel side out.
Now insert your On/Off pin with the groove in point outwards.

There's also a chance that your On/Off Pin is not the correct length.

If you suspect your sear, and this is an older mag, it's probably worth it to go ahead and replace it. If you see a lot of polishing on the tip that contacts the bolt, that could be an indication that it needs replacing.

[kjjm4]

I'm positive I've got the on/off together right now. There was an o-ring in the top half, I just wasn't getting ahold of it with the pick I was using. It has been replaced now. The leak did not go away.

The sear looks fine.

The only parts that can wear out that haven't been replaced are the sear, the entire on/off assembly, the spring pack, and the reg piston. What else could be causing my leak? I'm starting to get fed up, and I'm almost out of air too.

[eric_503]

what it says in the manual is that it could be a power tube oring leak or to try a shorter spacer other then that i dont know

[kjjm4]

I'm very nearly out of air, and none of the local fields are open during the week. BUT, I think the leak is getting smaller. I put the longest power tube spacer in, then I put 6 drops of oil in the ASA, and dry fired some, and the leak is now barely audible. I'm thinking that maybe enough dry firing may seat the new seals enough to stop the leak. We'll see after I get some more air. I don't want to dump much more money on parts for this valve, because I'm giving serious thought to getting an x-valve anyway.

[athomas]

A shorter spacer stops powertube leaking by allowing the bolt to contact the powertube oring closer to the front of the powertube.

A worn sear tip can cause powertube leaks but the shorter spacer usually fixes that problem. A bit of lubrication and exercise can help to seat the powertube orings.

You have an old on-off top. They work fine but you must remember to put the flat side towards the inside of the valve against the top 2 orings.

[rlmatthews]

I have that style on/off assembly in my kit.

The assembly should go in like this (Starting from the inside)

Brown (or yellowish) oring at the bottom of the opening.
White teflon oring inside of the first oring.
Brass on/off top

the rest goes together like this:

On/off lower body with another white teflon oring on the recessed part on the top, and another brown/yellow one on the outside of the body. The whole thing has the on/off pin running through it. Insert it into the opening with the end with the teflon oring first.

I may be wrong, but your post seemed to state that you only had the one oring under the on/off top, and you really need them both.

If these don't help, try changing the oring behind your power tube spacer and see if that helps.

Hope this helps!

Ryan

[paintman1142]

BOO ANS ON/OFF TOP, oh what the heck, BOO ANS!!!!

[athomas]

Its not an ANS on-off top. It is an old AGD on-off top.

[SpitFire1299]

The tripple fire and double fire thing is called bouncing, which is very common, and can be fun if you get good at it. :D

Anyway, does your rail/trigger frame have a bushing in it?

http://www.tunamart.com/images/product/175.jpg

[kjjm4]

Like where would the bushing be? Around the sear pin? There isn't one there. This gun doesn't have a rail, its a micromag, the rail and the body are integrated.

I already replaced all of the o rings, and I'm positive I have it together correctly. The leak is really slow now, and I think it will go away with a shorter powertube spacer. I don't have any air right now though.