I found the article very informative about replacing the seals on my Crosman 760. I also found out it was made in July 1970. Thank you. After replacing 3 of the 4 seals and reassembling the BB gun, it still will not pump up and hold air. The 4th seal in the replacement kit just did not look compatible. I noticed when I took the brass valve apart the spring was corroded a little and only one plug came out. It looked like another piece was still up inside. Any suggestions?
Crosman Crosman 760 1970 won’t pump up
- Thread starter Scott_760
- Start date
The valve in that model resets after firing, so it doesn't need to be cocked.
Fom what the OP is saying, it sounds like it isn't keeping the air pushed into the valve. Does it hiss from the rear of the barrel when you pump it? If so, that's a leak in the quad-seal side of the valve. If it won't take the air in the first place, then the problem is on the pump end of the valve.
Here's the parts diagram.
I had one come home from the flea market rather crusty on the inside, but it cleaned up and shoots just fine.
Cheers,
J~
Fom what the OP is saying, it sounds like it isn't keeping the air pushed into the valve. Does it hiss from the rear of the barrel when you pump it? If so, that's a leak in the quad-seal side of the valve. If it won't take the air in the first place, then the problem is on the pump end of the valve.
Here's the parts diagram.
I had one come home from the flea market rather crusty on the inside, but it cleaned up and shoots just fine.
Cheers,
J~
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Simple air guns to work on, if you need the valve cap quad ring let me know. I bought 50’of them
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I don’t hear any hissing. It just feels like air is not getting trapped at all. I am probably not describing this very well. The inside of my valve did not look nearly as bad as that one. Does the felt pad need well oiled on part 760-042?
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You're explaining it fine.
Yes, that should be oiled. Non-detergent 30w is not a bad choice. The pump-cup needs a little oil to seal with. Try oiling it and we'll see where that gets us. Do you feel any resistance when you close the pump?
Cheers,
J~
Yes, that should be oiled. Non-detergent 30w is not a bad choice. The pump-cup needs a little oil to seal with. Try oiling it and we'll see where that gets us. Do you feel any resistance when you close the pump?
Cheers,
J~
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Okay I just tried an experiment. I opened the pump handle and laid the BB gun on its back. I got the pump handle started and it closed on its own except for snapping onto the tube of course. There was very little resistance down. It didn’t slap down instantly. It was a gradual down. It did not stay in an upright position like as if it there was a good seal. Here is a pic fully opened. This is my BB gun from when I was a kid a long time ago so I would like to get it operating again.
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Okay. It sounds as if the piston pump-cup is getting somewhat of a seal. Does it spring back open when you pump it quickly? If so, then the seal within the pump-side of the valve (part #1400-029) isn't holding the air in. You're probably going to have to pull it down and re-do it. Been there a few times... Cleaning the mating surfaces on the interior of the valve with 000 steel wool will help it seal better. Pell-Gun oil is good to use and you can get it at WalMart.
And I completely feel you on it being the gun of your youth. I looked for over fifty years to find one like my brother shared with me at Christmas in '67. Now it's something that I treasure. It's one of the ways I remember him.
Cheers,
J~
And I completely feel you on it being the gun of your youth. I looked for over fifty years to find one like my brother shared with me at Christmas in '67. Now it's something that I treasure. It's one of the ways I remember him.
Cheers,
J~
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Lol. No worries, Scott.
Here's a link to an actually good vid on rebuilding one. Crosman 761XL Rebuild - YouTube
Cheers,
Jeff
Here's a link to an actually good vid on rebuilding one. Crosman 761XL Rebuild - YouTube
Cheers,
Jeff
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That is good. Do you think REM oil is sufficient? I have that on hand. Otherwise off to Walmart I go….
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I wouldn't risk the REM oil. I don't know that it would hurt things, but Pell-Gun oil is formulated for pellet guns. Motorcycle fork oil works as well. Mixed with 80/90 gear oil it's great for airguns, but that's kinda getting into the weeds...
Cheers,
J~
Cheers,
J~
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Jeff
I wanted you to be the first to know. I shot my BB gun for the first time in probably 30 years today!!!! Thank you for your assistance and you tube videos. I took it down. Cleaned everything again. Oiled it up. Reassembled it and even managed to accidentally bend the one spt arm on the pump handle driving that pin back in. Pumped it up ten times and shot a bb thru a shoe box at point blank range. Thank you again!!! Scott
View attachment IMG_1404.jpeg
I wanted you to be the first to know. I shot my BB gun for the first time in probably 30 years today!!!! Thank you for your assistance and you tube videos. I took it down. Cleaned everything again. Oiled it up. Reassembled it and even managed to accidentally bend the one spt arm on the pump handle driving that pin back in. Pumped it up ten times and shot a bb thru a shoe box at point blank range. Thank you again!!! Scott
View attachment IMG_1404.jpeg
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That is awesome, Scott!
Congrats on getting it going. Hoping you get many years of enjoyment from it.
Cheers,
J~
Congrats on getting it going. Hoping you get many years of enjoyment from it.
Cheers,
J~
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