Thank you so much for making this video. I referenced it several times and was able to successfully restore my uncle's Benjamin 342 from 1979. I did find that the last lead washer wanted to move a bit making it difficult. But, I got it in. Also, thanks for mentioning the bolt-before-pump after reassembly. I thought for a second that something was incorrect. Fires like a champ now.
Thank you extremely insightful I just purchased one of these little pellet rifles something I’ve always wanted since I was a kid I’m sure that sounds like a broken record but seeing the inner workings for a guy like me makes all the difference in the world very appreciative
Overall a great video; very informative. The video description(which few people are going to read) does mention reversing the valve nut IF the threads are "buggered up". I assume yours was, as you're obviously putting it on backward. I don't want to criticize, I just think it's an important point that you could've made more clear while you were assembling the rifle. Thank you, nonetheless!
From Portugal Europe Thanks for sharing your info i did what you explained in your video and i cot my oldtimer working again... Thanks and i wish you al the best for 2025. Pieter Lops
I have a Benjamin 312 and am attempting to install a new outlet valve guide and outlet valve. I have watched the video several times and it is clear that I am doing something wrong because the force I must apply to compress the small intake spring, the large intake spring and the conical large exhaust spring is much more than you apply in the video. Because of that I trimmed about 3 coils off the conical large exhaust spring as suggested in another video. When I add the completely compressed length of those three springs, I get 2.104 inches. The uncompressed length of those three springs is 3.875 giving an available compression length of 1.771. When I run the valve guide retaining nut into the pump tube until it hits the threads (without the 3 springs) I marked the installation tool and it is 3.215 inches from the face of the retaining nut to the mark. When I install the new intake valve (ensuring it is fully seated with the brass side showing) and the 3 springs when I run the tool with the valve guide, exhaust valve, and retaining nut into the pump tube the mark on the tool is 1.881 inches from the end of the pump tube. I have epoxied the small end of the conical large exhaust spring onto the exhaust valve because it was not apparent that the projection on the exhaust valve was entering the small end of the exhaust spring when I placed the exhaust valve and valve guide in the pump tube. No matter how much force I put on the tool I cannot get the retaining nut to engage the threads inside the pump tube. The fact that the 3 springs can only be compressed 1.771 inches seems to make it impossible to compress them 1.881. What am I doing wrong? - the parts I am installing are in the order shown in your video and the valve body is the same as the old one except for it having a circumferential groove that makes the orientation of the valve body irrelevant.
3 springs? Should only have the intake valve spring (shorter, copper spring) and the exhaust valve spring (bigger, steel, may be tapered or conical). Not sure where the other spring goes, unless it is the hammer spring, which goes on the outside (hammer side) of the exhaust valve nut.
The exhaust valve is a modified Sheridan that Crosman came up with why do you keep putting the valve nut on backwards the tapered side goes against the lead seal to squish the lead seal to make it seal up
Thank you for the highly instructional video. I was able to refresh my 312 and successfully install the valve. Now I am trying to source a pump cup, or a conversion kit that will work with my old Benjamin. Mine has the leather cup, and I know it would be better and easier to maintain with a rubber u-cup. Any ideas where to find a conversion kit or parts? Thanks!
Wow, leather cup!! that may be a replacement seal itself. But there are several sources for new pump cups, try Rick Wilnecker at Precision Pellet or Baker Airguns (google them). Also get a new felt while you are at it. Congrats on getting the valve to seal up, nice job!!
Thanks for the reply, Jonathan! I just ordered a "Benjamin Rifle 310 312 317 342 347 Piston Pump Head Fitting 3453 New Old Stock" from eBay, and I'm hoping it will work to convert to a rubber u-cup. The seller said it would work, and I have a u-cup that came with the Pyramid kit. I also phoned Mac1, and spoke with the gentlemen there, who made it clear that he doesn't sell obsolete parts, and was mainly interested in rebuilding. He didn't want to spend much time talking about it. My rifle may be a forties model because it has a leather seal, and I can't verify because it has no serial number either. I'll look into your suggestions. Thanks again!
I have a late 90's 397pa , it may have the later valve. Are special tools required to required for this like the early models? How can I tell what I have before taking it apart ?
I'd be surprised if it had the earlier soldered valve. But you can pull the end plug, hammer and spring, and see if there is a square looking thing in the tube. If there is, you have a soldered valve, if not, a cartridge valve and no special tool is needed.
Sorry, my dimensions are imperial. But take a look here; th-cam.com/video/fANHrU0bQmo/w-d-xo.html we have a drawing of the tool within the first 4 minutes.
You got The valve lock nut installed backward?, the champher on the lock nut should face the lead seal to compress and flare the lead ring to properly seal valve,. per factory instructions.
the black seals are generally of a softer material, which makes it easier to seal against the valve seats. Harder, generally white seals, perform better in that they lift off the seat faster and also don't extrude or degrade over time. But they are less forgiving of any imperfection on the valve seat.
yes, the front end, anyway. Not the valve end. It can be a pain. So measure the length of the existing pump rod when you initially take it out, for a starting point. Use a pin or punch on the front plug instead of screwing/unscrewing everything every time (or pounding on pins if you have a 342/7 or Sheridan.). Easier if you do it while the valve is out. By recollection, the threads on the rod are either 20 or 28 tpi, so a full turn of the rod gives 1/20” or 1/28” of adjustment to the length. can take a while to get it right. Patience!
Awesome tutorial. I have a problem with a Benjamin 397G that I think is a seal. When I install a new CO2 canister it seems to seal OK but when I make the first shot it is very weak and all the gas leaks out into the tube. So I suspect the seal that the CO2 canister seats against is damaged or missing. Do you have a tutorial on how to remove and disassemble a 397G valve?
I'm not that familiar with the 397G, but IIRC, the first shot pierces the co2 canister, then should shoot ok after that. So first shot weak is normal. 'Leaks out into the tube', I'm not sure what you mean, after the canister is pierced, the co2 is supposed to flow into the tube, which puts the gas in place for the next shots. Just as long as it doesn't leak out of the tube. Try the Vintage Airgun Forum, there should be someone there that has worked on these. Sorry I couldn't be more help.
no problem...thanks for the reply. Yeah, the gas leaks out of the gas canister into the tube the canister slides down when installing it, then out of the tube/gun altogether through a hole near the end. From what you are saying it must be the seal the canister rests on. If the first shot pierces it that would explain it. No power in the first shot at all, when there always was, and complete lose of CO2...you can hear it escaping. Now, how to get at that seal? I have a terrible feeling I may need that tool you describe making. Are they for sale commercially? I'll try the vintage guys....thanks again.
With the two port valve it should be much easier to assemble, right? What was the name of the parts kit with the synthetic seals? Does the two port valve come in a parts kit?
Hello Bennett, yes, two port valve is easier since you don't have to worry about orientation. But, there is a groove in the thread and seat of a 1-port valve compression chamber that the tab on the 1-porter helps to seal up. So it may not seal properly if you simply use the 2-port valve with lead or black synthetic seals, happens occasionally. The Mac1 kit with the white synthetic seals are the best I've found if you simply want to swap out valves, seem to seal both the 1-port and 2-port valves. So, I'd use that kit if swapping valves. Valves usually don't come with any kit that I'm aware of. There are numerous venders that sell seal kits, Mac1airgunshop.com, pyramid air, baker airguns, or precision pellet come to mind. The latter two may also have parts like the 2-port valve.
Awesome video! I have an old 60s Sheridan that needs to reseal an the barrel has become separated from the pump tube about 2 inches from the front sight to the rear ! how would i be able to weld it back? A have read of several people using JB WELD. but i don't want to go the route. thanks
If you don't want to use JB Weld you can soft solder it with 50/50 or you can use a low temperature refrigeration welding rod. I have had success with both !
How do you recommend cleaning these old brass barrels so you end up with an even patina color? (i.e. not bright brass in some areas)? Thanks for the video!
There are lots of places to get kits, Baker Airguns, Precision Pellet, and others. Even ebay ( look under Sheridan seal kits). The premier kit is from Mac 1 Airgun Shop. Will last forever, but also demands that you install in a clean environment and with smooth, defect free (polished, see my polishing tool video) seal seats. Other kits may be more forgiving but will not give quite as good of performance.
The only place I could find the pre-1995 kit was at Pyramid Air. www.pyramydair.com/s/a/Benjamin_Sheridan_Repair_Kit_Fits_Some_Pre_1995_Multi_Pump_Guns_w_Soldered_Valve/624
Thank you so much for making this video. I referenced it several times and was able to successfully restore my uncle's Benjamin 342 from 1979. I did find that the last lead washer wanted to move a bit making it difficult. But, I got it in. Also, thanks for mentioning the bolt-before-pump after reassembly. I thought for a second that something was incorrect. Fires like a champ now.
Thank you so much for making this series of videos. My 1972 blue streak now looks and shoots like new. I couldn't have done this without these videos.
Cool, makes it worth it. Thanks for letting me know.
Thank you extremely insightful I just purchased one of these little pellet rifles something I’ve always wanted since I was a kid I’m sure that sounds like a broken record but seeing the inner workings for a guy like me makes all the difference in the world very appreciative
Overall a great video; very informative. The video description(which few people are going to read) does mention reversing the valve nut IF the threads are "buggered up". I assume yours was, as you're obviously putting it on backward. I don't want to criticize, I just think it's an important point that you could've made more clear while you were assembling the rifle. Thank you, nonetheless!
I just purchased a beautiful old blue streak that needs seals. Thank you for this video.
From Portugal Europe Thanks for sharing your info i did what you explained in your video and i cot my oldtimer working again... Thanks and i wish you al the best for 2025. Pieter Lops
I have a Benjamin 312 and am attempting to install a new outlet valve guide and outlet valve. I have watched the video several times and it is clear that I am doing something wrong because the force I must apply to compress the small intake spring, the large intake spring and the conical large exhaust spring is much more than you apply in the video. Because of that I trimmed about 3 coils off the conical large exhaust spring as suggested in another video.
When I add the completely compressed length of those three springs, I get 2.104 inches. The uncompressed length of those three springs is 3.875 giving an available compression length of 1.771. When I run the valve guide retaining nut into the pump tube until it hits the threads (without the 3 springs) I marked the installation tool and it is 3.215 inches from the face of the retaining nut to the mark. When I install the new intake valve (ensuring it is fully seated with the brass side showing) and the 3 springs when I run the tool with the valve guide, exhaust valve, and retaining nut into the pump tube the mark on the tool is 1.881 inches from the end of the pump tube. I have epoxied the small end of the conical large exhaust spring onto the exhaust valve because it was not apparent that the projection on the exhaust valve was entering the small end of the exhaust spring when I placed the exhaust valve and valve guide in the pump tube. No matter how much force I put on the tool I cannot get the retaining nut to engage the threads inside the pump tube. The fact that the 3 springs can only be compressed 1.771 inches seems to make it impossible to compress them 1.881.
What am I doing wrong? - the parts I am installing are in the order shown in your video and the valve body is the same as the old one except for it having a circumferential groove that makes the orientation of the valve body irrelevant.
3 springs? Should only have the intake valve spring (shorter, copper spring) and the exhaust valve spring (bigger, steel, may be tapered or conical). Not sure where the other spring goes, unless it is the hammer spring, which goes on the outside (hammer side) of the exhaust valve nut.
Duh. The video clearly shows 2 springs not 3. Now I need new seals as I messed them up with all my assembly attempts. Thanks.
Great video it will definately help me do my 1970 silver streak!
Very good teacher. How about working with Benjamin pistols?
The exhaust valve is a modified Sheridan that Crosman came up with why do you keep putting the valve nut on backwards the tapered side goes against the lead seal to squish the lead seal to make it seal up
THANKS VERY HELPFUL INFOFMATION
Thank you for the highly instructional video. I was able to refresh my 312 and successfully install the valve. Now I am trying to source a pump cup, or a conversion kit that will work with my old Benjamin. Mine has the leather cup, and I know it would be better and easier to maintain with a rubber u-cup. Any ideas where to find a conversion kit or parts? Thanks!
Wow, leather cup!! that may be a replacement seal itself. But there are several sources for new pump cups, try Rick Wilnecker at Precision Pellet or Baker Airguns (google them). Also get a new felt while you are at it.
Congrats on getting the valve to seal up, nice job!!
Thanks for the reply, Jonathan! I just ordered a "Benjamin Rifle 310 312 317 342 347 Piston Pump Head Fitting 3453 New Old Stock" from eBay, and I'm hoping it will work to convert to a rubber u-cup. The seller said it would work, and I have a u-cup that came with the Pyramid kit. I also phoned Mac1, and spoke with the gentlemen there, who made it clear that he doesn't sell obsolete parts, and was mainly interested in rebuilding. He didn't want to spend much time talking about it. My rifle may be a forties model because it has a leather seal, and I can't verify because it has no serial number either. I'll look into your suggestions. Thanks again!
I have a late 90's 397pa , it may have the later valve. Are special tools required to required for this like the early models?
How can I tell what I have before taking it apart ?
I'd be surprised if it had the earlier soldered valve. But you can pull the end plug, hammer and spring, and see if there is a square looking thing in the tube. If there is, you have a soldered valve, if not, a cartridge valve and no special tool is needed.
Thank you very much for this wonderful video. I also want to know what is the size of the key, is it 8m
Sorry, my dimensions are imperial. But take a look here; th-cam.com/video/fANHrU0bQmo/w-d-xo.html
we have a drawing of the tool within the first 4 minutes.
You got The valve lock nut installed backward?, the champher on the lock nut should face the lead seal to compress and flare the lead ring to properly seal valve,. per factory instructions.
This is a SUPER helpful video - THAK YOU!
Mr. NWAG,
Can you tell me what action you take to remove the leftover pump cup residue from the front of the valve.?
Well, you can check this; th-cam.com/video/XOnpWFvCLxo/w-d-xo.html at the 24:10 mark, for how to clean and polish the exhaust valve.
Is one able to use a multi-port valve from a 342 in a 312 that initially used a single ported keyed valve?
I am rebuild my sheridan air rifle and I was wondering if the synthetic seals are better than the black seals that come in some kits?
the black seals are generally of a softer material, which makes it easier to seal against the valve seats. Harder, generally white seals, perform better in that they lift off the seat faster and also don't extrude or degrade over time. But they are less forgiving of any imperfection on the valve seat.
@@NorthWestAirgun Thank you!
@@NorthWestAirgun would it be a good idea to replace the springs too or reuse them?
@@jerryees original springs are generally ok to reuse
@@NorthWestAirgun Thank You again!
Perfecto well done, I can see that optimum pressure will happen when the pump arm applies max pressure to the valve, how do we achieve that?
Thanks for the video. Helps a lot. To adjust the stroke of the pump arm/seal rod, do you have to disassemble each time you make an adjustment?
yes, the front end, anyway. Not the valve end. It can be a pain. So measure the length of the existing pump rod when you initially take it out, for a starting point. Use a pin or punch on the front plug instead of screwing/unscrewing everything every time (or pounding on pins if you have a 342/7 or Sheridan.). Easier if you do it while the valve is out. By recollection, the threads on the rod are either 20 or 28 tpi, so a full turn of the rod gives 1/20” or 1/28” of adjustment to the length. can take a while to get it right. Patience!
Awesome tutorial. I have a problem with a Benjamin 397G that I think is a seal. When I install a new CO2 canister it seems to seal OK but when I make the first shot it is very weak and all the gas leaks out into the tube. So I suspect the seal that the CO2 canister seats against is damaged or missing. Do you have a tutorial on how to remove and disassemble a 397G valve?
I'm not that familiar with the 397G, but IIRC, the first shot pierces the co2 canister, then should shoot ok after that. So first shot weak is normal. 'Leaks out into the tube', I'm not sure what you mean, after the canister is pierced, the co2 is supposed to flow into the tube, which puts the gas in place for the next shots. Just as long as it doesn't leak out of the tube.
Try the Vintage Airgun Forum, there should be someone there that has worked on these. Sorry I couldn't be more help.
no problem...thanks for the reply. Yeah, the gas leaks out of the gas canister into the tube the canister slides down when installing it, then out of the tube/gun altogether through a hole near the end. From what you are saying it must be the seal the canister rests on. If the first shot pierces it that would explain it. No power in the first shot at all, when there always was, and complete lose of CO2...you can hear it escaping. Now, how to get at that seal? I have a terrible feeling I may need that tool you describe making. Are they for sale commercially? I'll try the vintage guys....thanks again.
Any idea if I can mail mine in for repair?
northwestairguns.com/where-can-i-get-my-vintage-airgun-repaired/
@NorthWestAirgun thank you! Not sure what the policy is for mailing air rifles...
With the two port valve it should be much easier to assemble, right? What was the name of the parts kit with the synthetic seals? Does the two port valve come in a parts kit?
Hello Bennett, yes, two port valve is easier since you don't have to worry about orientation. But, there is a groove in the thread and seat of a 1-port valve compression chamber that the tab on the 1-porter helps to seal up. So it may not seal properly if you simply use the 2-port valve with lead or black synthetic seals, happens occasionally. The Mac1 kit with the white synthetic seals are the best I've found if you simply want to swap out valves, seem to seal both the 1-port and 2-port valves. So, I'd use that kit if swapping valves.
Valves usually don't come with any kit that I'm aware of. There are numerous venders that sell seal kits, Mac1airgunshop.com, pyramid air, baker airguns, or precision pellet come to mind. The latter two may also have parts like the 2-port valve.
Awesome video! I have an old 60s Sheridan that needs to reseal an the barrel has become separated from the pump tube about 2 inches from the front sight to the rear ! how would i be able to weld it back? A have read of several people using JB WELD. but i don't want to go the route. thanks
If you don't want to use JB Weld you can soft solder it with 50/50 or you can use a low temperature refrigeration welding rod. I have had success with both !
How do you recommend cleaning these old brass barrels so you end up with an even patina color? (i.e. not bright brass in some areas)? Thanks for the video!
Do you do repair work on these air guns and if so how much would it cost to have a valve ...gun repaired.
Fence Walker
No, I don't, but I can refer you to a couple of others who do. Shoot me an email to;
nwa@northwestairguns.com
NorthWestAirgun
I checked all the suppliers you sent me but, none had the two port valves?
Hmmm, ok, PM me at nwa@northwestairguns.com. I'll see what I've got.
Where did you get your kit for the valve repair?
There are lots of places to get kits, Baker Airguns, Precision Pellet, and others. Even ebay ( look under Sheridan seal kits). The premier kit is from Mac 1 Airgun Shop. Will last forever, but also demands that you install in a clean environment and with smooth, defect free (polished, see my polishing tool video) seal seats. Other kits may be more forgiving but will not give quite as good of performance.
The only place I could find the pre-1995 kit was at Pyramid Air. www.pyramydair.com/s/a/Benjamin_Sheridan_Repair_Kit_Fits_Some_Pre_1995_Multi_Pump_Guns_w_Soldered_Valve/624
Is that for this exact gun Karl??
where can I buy a valve body nut?
Try Baker Airguns or Precision Pellet. Google them. Both should have what you are looking for,
Where can I get the valve
Try Rick Wilnecker at Precision Pellet (airgunshop.net)
I don't know how to PM on Utube but, I sent an email to you?
Ive totally screwed mine up! Is there somewhere I send mine to do this job?
Dean, email me at ; nwa@northwestairguns.com