Small Leak From Invasion Ram/Bolt

MOTORHEAD · 10-03-2012, 01:41 PM

Got an Invasion in a trade today. Aired her up, a small leak was coming from the back of the gun. I can hear it through the bolt chamber, but it is very minimal. I shot the gun, which I could tell was over pressurized from the amount of kick and noise, so I figured that could be the cause of the leak.

I have been a strict timmie owner, so I screwed both the inline and LPR regulators to flush. That stopped the leak. I pressurized the regs by one turn in from flush on the inline and 1/2 turn in on the LPR, no shots. After some trial and error, I discovered the gun shoots fairly close to normal velocity, though I do not have a chrono on-hand, when the inline is be about 1 1/2 turns in from flush, and the LPR about three from flush. The leak still occurs though, starting when I turn the LPR even just slightly in from flush.

I assume the cause of the leak is either in the ram or the LPR, so I will clean both when I have the time.

In the meantime, anybody have any ideas as to what exaclty may be the cause of the leak? And, considering I have no pressure testers nor chrono, what ammount of turns in from flush do most invasions run at? Just so I have a basic idea of where I need to be.

Thanks

MOTORHEAD · 10-03-2012, 01:45 PM

By the way, I am shooting with a Ninja SLP reg on my tank

Jack Rice · 10-03-2012, 04:41 PM

Quote:

Originally Posted by MOTORHEAD

screwed both the inline and LPR regulators to flush. That stopped the leak. ... The leak still occurs though, starting when I turn the LPR even just slightly in from flush.

We changed the spring in the gun right after we introduced it. Too strong and it was either on or off. You can tell if you have the old spring - you can back out the set screw and the air will turn of completely - new spring still has air pressure to bolt.

The question that comes to mind is: Does the gun shoot when there is no leak? ... that is to say is the LPR high enough to move the rammer with enough force?
If so then you are turning until the solenoid is overpressurizing. Again a too strong spring means that in just a turn or so you go from more than enough pressure to too much pressure. The original spring made is hard to adjust the gun to the softest setting.

If you have the new spring - then that is a bigger question.

MOTORHEAD · 10-03-2012, 05:13 PM

The gun will not shoot when the leak is not present, though the set screw on the LPR must be flush for the leak to go away.

The spring in my LPR is different than the one shown on page 19 of this manual http://www.alienpb.com/_images/compa...sionManual.pdf

Mine has many more coils.

Also, the leak will go away if I push the bolt forward just slightly. I don't have to move the bolt forward at all, just put pressure on the pin.

Is there a ballpark estimate as to how many turns in from flush on the inline and LPR get you in the range they need to be at?

MstrKey · 10-04-2012, 02:53 PM

If putting pressure on the bolt causes the leak to stop then my guess is one or more of the ram orings is in need of a change. Either on the striker part, or in the front of the ram body itself. The striker is my guess, since that's the most common one to go and usually results in air bypassing and leaking out the noid. Swap it out and see what happens.

MOTORHEAD · 10-04-2012, 08:00 PM

Great!

Anywhere that I can find the size for that O-ring?

MOTORHEAD · 10-04-2012, 08:29 PM

Or maybe a rebuild kit?

MstrKey · 10-05-2012, 02:00 PM

If you call alien direct I'm sure they will make you up a kit. Most of the orings are usually pretty standard from other kits though. Pop it off and look through the ones you have. You might get lucky.

MOTORHEAD · 10-05-2012, 02:57 PM

Cup seal was the culprit it looks like. Jack said they were 015, so I am going to try that out.

MstrKey · 10-06-2012, 07:31 PM

The cup seal is a piece of plastic isn't it? It's not an oring. The cup seal is the plastic part that seals the valve closed.

MOTORHEAD · 10-06-2012, 07:36 PM

From what I understand, the cup seal is the cylinder held behind the lpr and infront of the ram, held in place by the allen screw in the middle of the body. It has two #025 orings around it.

Maybe that is not the cup seal, but that is what is causing the leak

MOTORHEAD · 10-08-2012, 08:22 PM

Leak ended up coming from the oring between the ram and the ram housing. Got another one in there and we're good to go!

MstrKey · 10-09-2012, 10:32 PM

Ah you meant the valve. The cup seal sits on the stick(poppet) that goes through the valve. No worries you got the leak anyway. Good stuff. Someone proably just let the ram get too dry and it wore out.

Jack Rice · 10-09-2012, 11:38 PM

Quote:

Originally Posted by MstrKey

Someone probably just let the ram get too dry and it wore out.

Possible - but I think someone took the rammer out and cut it putting it back in. I would think it would take years for it dry out enough to leak. More problems are from over servicing than under servicing.

MstrKey · 10-10-2012, 03:06 PM

Quote:

Originally Posted by Jack Rice

Possible - but I think someone took the rammer out and cut it putting it back in. I would think it would take years for it dry out enough to leak. More problems are from over servicing than under servicing.

It's possible. I only say under lubing because the poster got the gun in a trade and people who don't service their gear properly usually sell/trade it off when something like a minor leak creeps up. No worries his gun is working now and will be for a long time hopefully.

Jack Rice · 10-10-2012, 04:15 PM

Quote:

Originally Posted by MstrKey

people who don't service their gear properly usually sell/trade it off when something like a minor leak

AND they do it without calling the shop.
It's amazing to me that a gun that will work perfectly gets sold without being fixed. The good thing is the new buyer calls me and we get it working - usually quite fast - and then they think I'm this really nice helpful guy. I only worry that the sellers may think the gun wasn't great. I worry that i n the end I have one guy saying " Call Jack he will take care of you" but I have another saying "yea, I owned a Alien once and it broke".
You do what you can

MstrKey · 10-10-2012, 11:05 PM

All you can do is what you're doing. Help those who are smart enough to ask.

WildWayz · 02-08-2013, 08:23 AM

Sounds like I have the same leak. VERY slight leak - barely hear it.
If I push back on the bolt (finger down chamber) it leaks a little more.

TBH could do with going through the entire marker and checking all orings, re-grease things etc. It was 2nd hand and 1st time I aired it up, it leaked from the ASA so had to replace the two orings there...

James

Jack Rice · 02-08-2013, 10:32 AM

If you let the last of the air out of the bottle by unscrewing the bottle, instead of shooting the gun, the O'ring can be streatched out of its groove - unscrewing the bottole another half turn allows the O'Ring to go back in it's groove - - but if you twist the bottle back in - before letig the O'Ring get seated again it cuts the O'Ring
During a break gass alows unscrew a extra half turn and you will not lose those bottle O'Rings

WildWayz · 02-08-2013, 10:34 AM

I did wonder why my Ninja's oring got cut and was poking out of the ASA hole...

Cheers Jack!

PS - the orings that were replaced were the 012's (from memory) inside the ASA, not the bottle.

Jack Rice · 02-08-2013, 11:12 AM

Just so you don't make anyone else nuts - inside the ASA - 014
012 go inside the Ram body and 011 go on the ram - those are the only ones that a player might reasonably replace - but they do last for years