GTA
All Springer/NP/PCP Air Gun Discussion General => Vintage Air Gun Gate => Topic started by: bantam5s on May 18, 2022, 12:22:27 AM
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When you pump you gun does it squeak ?
I was shooting my '65 140 and was reminded of a reason why I don't shoot it as often as I should, maybe more of a subconscious reason but a reason none the less.
It squeaks when I pump it, and no matter where I put oil I can not remedy this issue.
I don't see anything rubbing, but maybe theres something I'm missing.
Could it really just be becaise theres no felt wiper on the piston ?
(https://i.postimg.cc/DwBxHyHf/20220517-194418.jpg) (https://postimg.cc/zyHwR5q4)
These 140's are a great simple rugged gun, theres a lot to love with the only negative being the sliding cover bolt, but that squeak is annoying.
I'm not giving up on the gun, but I just can't figure out why it's squeaking when I pump it.
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I have a couple Sheridans that are the same way, and I've wondered how to get them to stop.
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I have had several 140/1400's over the years, & a couple of them squeaked. Never could get oil to the right place to stop it.
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The squeak could possibly be air passing by the check valve, like the reed on a wind instrument.
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The squeak could possibly be air passing by the check valve, like the reed on a wind instrument.
+1
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My pumpers have a repertoire of different squeeks, clicks and toots. I just live with them. ;)
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The squeak could possibly be air passing by the check valve, like the reed on a wind instrument.
It's a pretty loud squeak, but maybe that's it.
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I rebuilt one of mine with a Mac1 O ring piston. If I pump it briskly it will squeak right at the end of each pump stroke. Pumped a little slower it does not squeak. The tendency to squeak gets worse as the pressure goes up. I’m thinking my problem is the O ring seal “burping” air past the seal when it is pumped too hard. I’ve never heard a parachute seal squeak on any of my Crosman’s unless it needs oiling.
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I rebuilt one of mine with a Mac1 O ring piston. If I pump it briskly it will squeak right at the end of each pump stroke. Pumped a little slower it does not squeak. The tendency to squeak gets worse as the pressure goes up. I’m thinking my problem is the O ring seal “burping” air past the seal when it is pumped too hard. I’ve never heard a parachute seal squeak on any of my Crosman’s unless it needs oiling.
Sounds like you may have a belled out pump tube
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I rebuilt one of mine with a Mac1 O ring piston. If I pump it briskly it will squeak right at the end of each pump stroke. Pumped a little slower it does not squeak. The tendency to squeak gets worse as the pressure goes up. I’m thinking my problem is the O ring seal “burping” air past the seal when it is pumped too hard. I’ve never heard a parachute seal squeak on any of my Crosman’s unless it needs oiling.
Sounds like you may have a belled out pump tube
Thanks for the tip. I’ll check it with some calipers. Fortunately I have another 1400 pump tube if needed.
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I have bought seal kits from Crosman600repair in the past, but I looked through my Ebay purchase history and didn't see a 140 seal kit there, so I'm thinking I must have went with a Mac1 kit.
Then again maybe I got a kit from Bakerairguns?
I found a post where I mentioned having payed $35 for my seal kit, but I never mentioned where I got it.
I'm definitely not going to take my gun apart to see what kind of seal kit I have in it, not that knowing this would stop the squeaking.
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I rebuilt one of mine with a Mac1 O ring piston. If I pump it briskly it will squeak right at the end of each pump stroke. Pumped a little slower it does not squeak. The tendency to squeak gets worse as the pressure goes up. I’m thinking my problem is the O ring seal “burping” air past the seal when it is pumped too hard. I’ve never heard a parachute seal squeak on any of my Crosman’s unless it needs oiling.
Sounds like you may have a belled out pump tube
Thanks for the tip. I’ll check it with some calipers. Fortunately I have another 1400 pump tube if needed.
I hope that I was helpful. Usually you can tell by measuring the O.D. In various places. If you do find a bulge, you could repair it by swaging it with pre-bored soft jaws in a 3-jaw lathe chuck using a to size mandrel on the I.D.
IMHO, The usual cause of belling is from over pumping.
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My Benjamin 132 squeaks and my assumption was the inner chamber was wore from use. I am pretty sure the squeaking is from air escaping past the plunger. I made an o'ring plunger and that helped but it still is underpowered. I will have to check the OD for bellying. Thanks for the tip.
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My Benjamin 132 squeaks and my assumption was the inner chamber was wore from use. I am pretty sure the squeaking is from air escaping past the plunger. I made an o'ring plunger and that helped but it still is underpowered. I will have to check the OD for bellying. Thanks for the tip.
A backup ring may help.
https://www.sealingandcontaminationtips.com/backup-rings-help-prevent-o-ring-migration/ (https://www.sealingandcontaminationtips.com/backup-rings-help-prevent-o-ring-migration/)
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I rebuilt one of mine with a Mac1 O ring piston. If I pump it briskly it will squeak right at the end of each pump stroke. Pumped a little slower it does not squeak. The tendency to squeak gets worse as the pressure goes up. I’m thinking my problem is the O ring seal “burping” air past the seal when it is pumped too hard. I’ve never heard a parachute seal squeak on any of my Crosman’s unless it needs oiling.
I think it's making a tighter seal with that tough Durometer O-ring. If you pump fast, it's rigid enough to clear oil out of the way quickly, Causing a squeak. Not a bad thing because it's so durable.
It probably produces more pressure than the stock pump cup. I believe mine do.
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Anyone who can just avoid the squeak by pumping differently is lucky.
If I pump my gun quickly I don't notice the squeak as much, but there's basically no way to avoid it unless I have the gun in my lap upside down which is very awkward.
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I haven't tried a backup ring but I have plenty of area on the piston to try it. I think an o'ring should work. I do have some teflon seals from McMaster Carr that may fit. Think I will try double o'rings first and see what velocity I get. Thanks again.
Jim
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I haven't tried a backup ring but I have plenty of area on the piston to try it. I think an o'ring should work. I do have some teflon seals from McMaster Carr that may fit. Think I will try double o'rings first and see what velocity I get. Thanks again.
Jim
A buna-n o-ring energized teflon o-ring would probably work Great. Another thing that I sometimes do is to add another o-ring with some space between it and the sealing o-ring so I can put some “permanent” lubrication trapped between the two o-rings. My .02
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I've been shooting my 140 a bunch this week, and surprisingly it doesn't seem to be squeaking as much now.
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Kinda like a Woman....show her a little love and she quiets down.
Cheers!
Rich
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The squeak could possibly be air passing by the check valve, like the reed on a wind instrument.
Does this imply the check valve is leaking? My c362, definitely not "vintage", has both a slow leak and a squeak at the end of the stroke. Now I'm wondering if they are related. I never gave the squeak any thought until I saw this thread.
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The squeak could possibly be air passing by the check valve, like the reed on a wind instrument.
Does this imply the check valve is leaking? My c362, definitely not "vintage", has both a slow leak and a squeak at the end of the stroke. Now I'm wondering if they are related. I never gave the squeak any thought until I saw this thread.
Most likely not a sign, I have squeakers that hold air forever.
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Could be the pins thru the pump handle causing the squeak. Not unlike walking on a sub-floor with loose nails.
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Could be the pins thru the pump handle causing the squeak. Not unlike walking on a sub-floor with loose nails.
I've never thought of that.
It doesn't seem to be the kind of squeak, but I'm not sure I'd really know.