Crosman 140 trauma !

[hellsquad]

OK so after spending $60 on parts from canada that never came, trying to no avail to find a part, I ended up making a valve part out of a 1377 for my 140.
BUT
It is driving me mad, the QUAD seal....WTF am I doing wrong?? strip. fit, still a tiny leak through transfer port, repeated this 3 times now, driving me mad.
Not damaging seal, so what????
Help

[--ped--]

a good chance the valve rear body spigot is worn and i've often had to mix and match bodies to exhaust valve caps to get them to work
the quad can be a pain to fit and is even harder to make (not making another of those i spent all day getting one just right)
i a;lso found not all quads are as good as others and i now only buy them from one company
also check that the trigger isn't letting the block move back so the exhaust cap is only just on the spigot
you can make a longer connecting bar if this is the case

[hellsquad]

Thanks Ped, (without your info would not have even thought to use the 13xx part.)

OK so I sorted it, I read on a US forum that you can at a pinch use a 4x2 oring in place of the quad, I did it works very well !
It is tighter on the spigot, but as Ped eluded to this oring is tighter so issue gone..with this spigot LOL

I used the spring from the 13xx as well as there is more volume in the valve now (longer internal dia : ) so old spring to short.
Made custom pin to hold valve in place and JUST kept the rear oring out of the hole, keeping seal

GUN IS FINISHED phewwwww

[--ped--]

glad you got it sorted
i have plans to swap out the quad cap and steel port sleeve for a 1377 valve rear with a firing pin like a sharps

[T 20]

glad you got it sorted
i have plans to swap out the quad cap and steel port sleeve for a 1377 valve rear with a firing pin like a sharps

I've often wondered if it would be worthwhile fitting a 1377 rear valve body with a knob cocking hammer and the trigger unit off a QB79 ?

I have all the parts but I just never get around to it.



All the best Mick

[hellsquad]

With the 13xx back end with more volume it is giving 11ftlbs with 16gr at 7 pumps.
How does that compare to standard?

[--ped--]

a little better than normal all mine now have pressure relief pistons so mine will only do about 7fpe
i have a 140 tube on the bench and a 13xx valve and rear cocker just not had time to marry it all together Mick oneday perhaps but i also have a few falcons ahead in the queque

[hellsquad]

Mick / Ped.

If just for fun, no issue
But why go the cocking route at all? the 140 self cocking valve is great IMO?
cannot see a reason at the moment, I can maybe see problems with not fully dumping air (though second pumped shot may be less...ohh...).


I do agree the steel port sleeve is rubbish.
So why? fun or logic ?

[T 20]

a little better than normal all mine now have pressure relief pistons so mine will only do about 7fpe
i have a 140 tube on the bench and a 13xx valve and rear cocker just not had time to marry it all together Mick oneday perhaps but i also have a few falcons ahead in the queque

A bit like me then, Ped.

I have all the parts but I'd rather that my next project was converting a QB78 into a single stroke pneumatic.






Note to self --- stop playing with twangers and find some 27mm ID tube.




All the best Mick

[--ped--]

Mick / Ped.

If just for fun, no issue
But why go the cocking route at all? the 140 self cocking valve is great IMO?
cannot see a reason at the moment, I can maybe see problems with not fully dumping air (though second pumped shot may be less...ohh...).


I do agree the steel port sleeve is rubbish.
So why? fun or logic ?

converting to a 13xx valve with a rear cocker will be like a modern whaley and just to see how it works
i do also have a plan to make a valve rear that works like a sharps innova and uses the original seal block

[hellsquad]

converting to a 13xx valve with a rear cocker will be like a modern whaley and just to see how it works
i do also have a plan to make a valve rear that works like a sharps innova and uses the original seal block

OK mentioning the Whaley makes it make sence

I have simplified fitting the 13xx rear end on to crosman 140s though

1 machine flat the cone end on the 13xx unit
2 machine the standard stock fixing STUD to valve end thread down to m4 for 5mm, but leave enough of the old thread to "fill" and lock the stud to body hole.
3 Insert an extra oring between the valve and the steel port sleeve (this helps a bit as well on the seal/fps AND takes up the space of the shorter body )
4 adjust rod length.
SORTED
PS and the 2x4 oring is BETTER than the quad seal, holds no matter what

[--ped--]

interesting on the quad i'll give it a try next one i do

[hellsquad]

interesting on the quad i'll give it a try next one i do

Feels too tight, but works and returns very well