TargetTalk

I have a IZH-46M that pumps up ok but as soon as I close the loading gate it leaks the air out before the gate is latched.

I cleaned the valve assembly and it will work ok for ten or so shots and then starts to leak again. This is happening with a new main seal (and also with the old main seal)

The leak starts just before the gate is fully down. If I do not close the gate it holds the air just fine. The gate latches up tight, the seals on the gate are good.

What do I need to adjust?

I'd love to find a fix for this myself. The MIT team has a couple that are doing the same thing. Sometimes gently lowering the loading gate helps, but that shouldn't be necessary.

When the loading gate is up, there is a round camming surface on it that holds the valve closed so the various latching sear parts can engage. When the gate goes down, it releases the valve, and the sear/latch parts are supposed to hold it closed until you fire. Something is preventing that from happening, possibly dirt, or wear.

Ours are very well used, so I'm suspecting a wear issue, but I'm not sure what part(s) might need replacing. I'm also not sure how much tweaking & fitting is done at the factory, so I don't know if just dropping in a new "X" will fix it.

How old is yours?

The documentation that came with it indicates a build date of 28.04.10 (April 28, 2010). I bought the gun from a store that no longer sells them and got it as a "parts" gun, they indicated it had this problem. I thought it was probably the main seal and replaced it. It was a "new" gun that had been returned due to this problem so the store then sold it to me as a defective parts gun.

After replacing the piston cup-main seal it worked fine for about thirty shots and then started leaking again. I took the latch out and cleaned the parts 13, 9 and 17. It works ok for about ten shots and then starts to leak when closing the latch. If I let the gun sit for awhile it then works ok for a few shots but starts leaking again.

Is it possible to remove parts 30 - valve seat, 31 - locking piece and 32 - bushing? I am thinking there may be dirt or metal shavings in that area.

I think the problem is that #14 (Valve Sear) isn't holding #17 (Valve Plunger) closed hard (forward) enough. At least in the case of the MIT pistols, they did work OK for many years, which suggests a problem with either dirt or wear.

In the case of a new pistol that has never functioned properly, it's a bit harder to say. One of those two parts could be out of tolerance, or the parts could be OK, but the distance to the seal is longer than it's supposed to be.

I took it apart again and cleaned 13-valve spring, 9-valve and 17 valve plunger, ran a q-tip down 32-bushing, blew some canned air down the tunnel.

Re-lubed it, put it back together and it worked for about 40 rounds, then starts to leak out again.

Something happens as the latch is closed? The trigger seems to function properly even if there is no air (leaked out).

I am really not sure what the latch closing action could be doing to affect the sealing of the air chamber?

Maybe the latch closing has nothing to do with the leakage and it is just the timing of about when it happens? If you pump it and leave it alone for 10 minutes, does it them leak only when you close the latch?

There seems to be two conditions.

#1. As the pump stroke is finished, it then leaks. This is before the loading latch is closed or even moved.

#2. Holds air until the loading latch is in the final closing stage. I can pump it, walk away for 10 minutes or more, come back and as soon as I close the latch it leaks.

Neither condition is permanent. I can fire several shots, no problems then suddenly either number 1 or 2 starts to happen. Let the gun sit for 10 - 15 minutes, then dry fire a few shots expelling air only and suddenly it is ok again for awhile.

I am suspecting it is dirt somewhere in the valve system but I have cleaned and re-lubed it twice and it still happens.

I would think a bad valve - 9 or valve spring -22 would fail more consistently? The piston cup - 5 is brand new, installed & lubed just a few days ago.

You should call Tim at MAC 1 and ask him to see if he knows the problem.
It could be a defective valve.

http://www.mac1airgunshop.com/izh-46-va ... 46ss90.htm

try puting a rubber oring 6mmx2mm is what i used between barrel and hinge part 7 in diagram . http://my.tbaytel.net/coopers/BaikalIZH46MReview/
this stoped my leaks and lets the lever stay up at 90 degress without falling when being cocked.

try puting a rubber oring 6mmx2mm is what i used between barrel and hinge part 7 in diagram . http://my.tbaytel.net/coopers/BaikalIZH46MReview/
this stoped my leaks and lets the lever stay up at 90 degress without falling when being cocked.

This sounds promising, but once I figured out that the "hinge" is the flat linking plate that open the action during cocking, I'm confused as to exactly where the O-ring goes. Do you slip the O-ring over the barrel, or the "hinge", and where does the O-ring sit along the associated part?

Any chance we can get a photo?

Do yourself a small favour and take off the linking plate. Use some steel filled epoxy putty to glue a 3/8" neodymium magnet into the channel behind the breech lever, using some plastic film as a barrier and the transfer port block as the clamp to hold it until cured. Works a charm in holding the thing back on my Izzy. I tossed the unnecessary automatic parts, made it simpler: I just lift the thing manually and it sticks to the magnet until I'm ready to push it back down. Shaved a few grams of steel front weight there as a bonus.

I think I have the "leaking" problem solved.

I removed parts 17 - valve plunger, valve - 9 , and valve spring - 13.

Took a q tip moistened with Kroil and swirled it up and down in the bushing - 32 (where the above parts normally reside). After doing this until the q tips came out clean, took 3. Used canned air to blow out the tunnel in valve seat - 30 several times. Visually inspected and it now looked clean in there.

Put it all back together with some lube and have not had a leak in 60 some shots.

Here's hoping it was just the dirt that was causing this problem.

sit the oring flat between hunge and barrel

sit the oring flat between hunge and barrel

OK, I'll give it a try. Not sure how well it will stay in place, but I should have some appropriate sized O-rings some place in my collection.