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2240 gas leak

RDJT

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Hey everyone.
Firstly wanna say thanks for all the free info you give to me instead of paying out to a 3rd party.

I have my crossman 2240.
And I get a gas leak from the valve. Cooked or unchocked Theres a slight hissing. Even though not major it's a noise I do not want to hear.

today i stripped it and cleaned with oil remover (designed for airsoft guns. Thought I'd ad that I know that then2240 isn't aorsoft. But used it to clean grease before reapply)and cleaned solidly. But still.
Dunno why but i just checked and it wasnt hissing. I then cocked it and it was then hissing again.
and now its cocked. And theres no hissing no sound odlf leakage at all.
im gonna fire and see if it does again

again hissing once cocked. And bolt forward its hard to hear it as I'm listening from barrel entry..

im getting confussed as to where the problem is ( i beleieve valve ) . Could someone ahed some light ?

I will post pics below high shoe internals of what I only can ingrained being the problem.

Quick update.
It seems that leaving the gun alone for a shortish period 10 is mins )
The hissing/ leaking stops from both ends of the gun ( barrel n breach ).

Upon firing it then beginnings leaking but slows after a minute or 2.

I'd really like to fix this.
All helpfully replies are welcome
 

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Last edited:
Nice one
I really appreciate that guys.
I'm gonna order a whole new vslvr enclosure as ... eell I like ne things.
I'll keep this as spares.

I'm almost certain it's where I used a small power tool to increase valve volume for longer barrel
 
your valve stem is toast
looks to have been over heated when someone ground the stem
Yeah that would of been me ' urgh' lol.
I plan on ordering a longer barrel this week and new valve stem some o rings and make my stock.


Thanks for the advice guys!
 
i have no stems in stock but i keep oring sets in stock and do them cheaper on here than i sell them on evil bay
 
This is a good place for Crosman parts https://www.trrobb.com/category/crosman

The 2240 is very near the power limit, a lot of those mods are OK on the 2250 but will make the 2240 over the limit & illegal. A longer barrel could also make the pistol over the limit, you may have to either replace the hammer spring with a weaker one or cut it down to stay under the limit of 6 Ft/ lbs.

The co2 carts won't last a long either with an enlarged valve etc.

Well worth buying a chrono, even if it's a ten quid one off ali express.
 
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