GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: springer on March 07, 2011, 12:23:38 AM
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This gun was my brothers in the 80s, and it sat in the closet at the parents house.. without air in it, and pretty much dry rotted the rubber.
I have rebuilt it with new o rings on the piston, valve body opening, base of the valve pin.
It now holds air with up to 10 pumps... and fires well (although i don't think it gets the full 495 fps= wish i had a chrony)
The problem is, the pump handle pops out when more than about 4-5 pumps are in it. I suspect the valve isn't sealing and holding in its air, letting it get pressure back on the pump side.
Any ideas?
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The problem is, the pump handle pops out when more than about 4-5 pumps are in it. I suspect the valve isn't sealing and holding in its air, letting it get pressure back on the pump side.
Any ideas?
I think your right. Mine does that some times and I just add some oil and It fixes it.
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The service manual for the 880 says that if the pump handle pushes out after pumping then the chamber valve seal is leaking. I think it is basically the same internals of the 922. I can send you a copy in PDF if you PM me.
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I actually bought a new 880 to scrap and use for parts thinking it would have the same internals. Sadly the new 880 had a slightly different piston, compression tube, valve and body, making the parts not exact replacements. (plus i really like the 880 and didn't have the heart to part it out after holding it and shooting it) I think i could swap the whole piston/compression tube, valve assembly if need be, but i suspect the problem is solveable w/out this.
The part i think that really is comprimised, is where the aluminum cap of the valve has to press against the brass compression tube, to maintain an airtight seal, WITHOUT an O ring. Iam only using silicone oil as a sealant, maybe i need something thicker for this particular part.
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The new 880 is different than the older version 880 that I sent you information for. I hope it helps.
Wade
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The part i think that really is comprimised, is where the aluminum cap of the valve has to press against the brass compression tube, to maintain an airtight seal, WITHOUT an O ring. Iam only using silicone oil as a sealant, maybe i need something thicker for this particular part.
I haven't looked at your parts diagram but on my 880 right behind that aluminum cap I do have a sorta cupped seal to hold the pressure in. One thing I did on mine was fit a o-ring in that cuped seal to kinda stretch it out more...it worked peachy for me.
Cell
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I have rebuilt it with new o rings on the piston, valve body opening, base of the valve pin.
It now holds air with up to 10 pumps... and fires well (although i don't think it gets the full 495 fps= wish i had a chrony)
In the pic make sure that rubber spacer isn't to soft. If it is it will compress to much and won't allow you to pump to maximum pressure. I went ahead and just replaced it with a solid metal spacer on my 880...it really increases the pressure( I think it shoots in the 800 fps range but will chrono it in a few days.) so the seals might go bad faster than if it was stock. It also makes it harder to pump 10 times for a young kid.
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So my 922 parts look pretty much just like that pic cell posted. The area you are pointing to, i did replace with two solid rubber washers that fit perfectly snug inside the tube, and a new o ring on the piston right in front of it. It still leaks.
My thought was that the problem was on the other side of the chamber, by the valve. See how that aluminum cap presses against that indented part of the brass tube. I figure thats where some pressure is leaking back, thus letting the pressure get back on the front of the piston whent its in the closed position.
In theory, the valve should work as a one way valve allowing added pressure in with each pump. So that aluminum cap should block off the pressure... or am i missing something.
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That cap doesn't make the seal, the rubber piece behind the cap does. When you pump the piston it forces air into the chamber. That air then puts pressure on the rubber seal to expand it's "cup" tight on the cylinder walls...keeping the pressure in. Where do you hear it leaking? From the muzzle or at the transfer port?
That pic is from a 922 break down I found on the net so it should be just like you have. It actually looks my 880 which is from the early '80's also.
Cell
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I'm glad you all are posting here
I rebuilt an 880 using Teflon tape around the rubber spring thing it was shooting 660fps cphp 10 pumps the tape must be giving because it takes more pumps to get there
it has proven its self a keeper
im thinking the rubber spacer you replaced with a metal one may be to blame i dont hear any leaks when pumping just a soft pump until around 7-9 then it gets harder
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sorry, i didn't mean to imply that i could hear it leaking. I was thinking that pressure was leaking from the valve back to the compression chamber. i can't believe i missed it, that rubber seal Behind the aluminum cap of course is the seal. I wonder if i can't get a new one of those. Mine appears in perfect shape, but i suspect its the problem.
" rubber spacer you replaced with a metal one "- i didn't replace the rubber spacer with metal. I used two 1/2" rubber washers in place of that big soft rubber spacer. The old one had been shredded and was not identifieable. I think they do fine, the O ring is what provides most of the seal, they just keep the piston straight in the cylinder.
Thanks for all the input guys
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Here is a few links for a how to and spare parts.
http://www.jgairguns.biz/catalog/index.php?cPath=78&osCsid=0b99e0c7f4fbc67c067065a0c25aaff5 (http://www.jgairguns.biz/catalog/index.php?cPath=78&osCsid=0b99e0c7f4fbc67c067065a0c25aaff5)
file:///C:/Documents%20and%20Settings/Patrick/Desktop/880%20powerline%20breakdown.htm
Like I said. The thing I did was put a o-ring that was a little bigger than that seal inside the seal it's self. It's just a temp fix but seems to holding up under the extra pressure I have with the metal piston spacers.
Cell
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Thanks for the link to JGairguns, i had never been there.
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opps...guess you can't read the link of my desktop :P
https://daisymuseum.com/forum/forum_posts.asp?TID=3519&OB=DESC&PN=2
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For future readers with a similar issue. Here is a very useful guide on this family of Daisy rifles with lots of great pics.
http://www.daisymuseum.com/forum/forum_posts.asp?TID=3519 (http://www.daisymuseum.com/forum/forum_posts.asp?TID=3519)
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Is there anyone that works on these? I had a chance to get a broken 22SG but couldn't find anyone who would work on it. I was willing to pay, but everyone said no. So, I let it go. I would love to get an old wood stock 922 if I found one.
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had this guy seal mine
http://tmacsairgunservice.com/ (http://tmacsairgunservice.com/)
he works with B&A / Ron Sauls every so often if Ron has an inventory backup
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Is there anyone that works on these? I had a chance to get a broken 22SG but couldn't find anyone who would work on it. I was willing to pay, but everyone said no. So, I let it go. I would love to get an old wood stock 922 if I found one.
I have a NIB Daisy 922 with the wooden stock and forearm. Actually have it listed at American Airguns Classified titled: NIB 1991 Daisy 922 .22 Cal