1377 Brass Valve

[rr_shooter]

Have a Phase 2 1377 that I bought in the late '80s.  Yesterday, I noticed it wouldn't hold pressure - I could hear the air coming out the barrel with each pump.  Changed both the o-rings in the valve, but that didn't solve the problem.  "Borrowed" an aluminum valve from another newer 1377 that I'm doing some work on, and the pistol pressurized fine.

Figured the issue is with the valve stem.  The stem has a brass cap with a molded seal around the stem.  My question, will the newer valve stem with the molded (Delrin?) cap work with the valve seat in the brass valve?  Or is the solution to buy an new valve assembly?

I presume the old brass valve stem isn't available any longer - will call Crosman on Monday.  Has anyone had any success in changing out the seal on the brass valve stem?  (Looking to keep it "vintage")

[Rob112o]

I've had success on changing out the oring from inside the valve stem. It's a pain in the butt to get out, but it can be done. You might get lucky and the stem part will unscrew from the base with the rubber seal. I went to the hardware store to the plumbing section and found a oring that fit perfectly. This was on a Dan and I've had no problems. On a couple Benjamin's I've had the ones that unscrew. Again they've all had no issues.
   If that oring is rock hard I got my smallest drill bit and drilled a bunch of holes into it. Which gave me holes to insert picks and such to pry and crack pieces of it out.

[rr_shooter]

Thanks for the response, Rob. 

From what I can see, the existing valve stem does not use an O-ring.  Here's a photo of the existing:



Here's a photo of an aftermarket stem (from GMAC):



Here's a picture of the valve seat - doesn't appear to have a flat surface for the seal:



The type of valve stem used in my newer 1377 (and the one I will presume Crosman carries as a replacement) is shown here:




It appears both the old and the new use a harder material (I presume Delrin) as a sealing surface.  I'm not sure I could remove the existing seal to replace it with an O-ring without screwing up the brass head.

If I need to go with a current Crosman replacement part (not really keen on buying replacement parts for an American product from across the pond), is the 1377 part the best replacement?  I've heard people complementing the overmolded poppet used on the Disco - anyone know if that will fit in the old style 1377 valve?

[bgmcgee]

The disco's stem diameter is larger than that of the 13xx stem. I would try the new part as is as it may seal.  No real harm in trying except time.

[rr_shooter]

Thanks, for the info on the Disco, Barry.  I'll go with the newer-style 1377 stem and see how it works.

[bgmcgee]

Let us know if it works or not.

[ped]

new stem seals fine in older brass valves

[rr_shooter]

Thanks for the help, guys.  Will post if any problems but from "ped's" comment, there shouldn't be any.

[bgmcgee]

Ped is the man. If he says it will work then it will.

[ped]

cheers Barry for the vote of confidence
I've fitted a few of the newer stems to brass 13xx valves ,i've even fitted them to 766's a 2200 and believe it or not a MK1(stems had to be adjusted for length)
with any reseal you need to check the condition of the sealing faces and with harder seal materials you may have to  lap them in , a bit of toothpaste is what I use if needed

[rr_shooter]

ped - what tool do you use to lap the seat?  Old valve stem?  New valve stem?  Something else?

[ped]

you use the new stem

[rr_shooter]

Thanks, ped!

[jim p]

I tried a new valve stem about 3 months ago.  I did not lap it in and it did not work.  I went with the new weaker aluminum valve.