GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: Weiand on September 21, 2017, 05:39:05 PM
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Old Blue '74 Sheirdan Blue Streak
Seems the work I did a while back has un - done itself.
So now, I need to be pointed in the direction to purchase the tool for remove / install the "guts".
First time I did the job I was loaned one. Time for me to get my own now.
Since she'll need a rebuild 'gain cuz won't hold air anymore yet 'gain.
I'm tinkin' 'bout a few "upgrades" since she'll be apart, as well as a good clean up & re-finish / paint job jus' so she look's better to me when I shoot.
I had a few websites / pages saved a while back with some parts, but those were lost durin' a H.D.D. failure.
So a point in the direction of sum parts as well.
Want to get her back to hittin' hard 'gain an 'mebbe e'en bump up the power a bit an dress her up sum.
As well, I've been lookin' at the 392 that are for sale new on Pyr. Lookin' like a nice hard hitter an may need to find it's way into my "collection"
I do have on the way to me a Chrono. Prob not the "best" there is, hopfully not garbage, but $74.00 seem'd like a nice deal and SHOULD do a lot better job than me jus' guessin' what the FPS is.
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Baker Airguns for the tool, Mac1 for rebuild parts
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Here is what I did... (Bargain Shopper)
Bought the Sheridan/Benjamin Rebuild Kit from Pyramyd Air just to get the Tool... plus some spare parts if needed.
Then I contacted Rick at Precision Pellet for the correct parts for my specific gun.
I have rebuilt several "Soldered in Valve" guns since and use the same tool. Always contacting Precision Pellet for the parts... and still have some of the original purchase PA seals left.
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Now... for you comment on a new 392... DO IT!
If you shop around you can find them for about $120-130.... Darn nice gun!
Just take some acetone (nail polish remover) on a Q-tip to the crown for the known over spray problem first.
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Notes taken down.
Mac1 I'm sure that's one 'o the sites I had bookmark'd then lost, sounds very familair, I tink where I got the first rebuild kit an my secret sauce.
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The "advertised" fps on the 392 makes it seem like a nice hard hitter, but, ya know, "advertised" is usally a lot diff than what one gets.
I mean, jus' goin' by Old Blue usin' 13.73 gr. .20, seem's that 392 would do quite well with a 16 or so gr
Grant'd, once my "cheap" chrono shows up, I can find out, well unless I bought a complete piece of junk, but ya know, gotta get it to find out.
I already like the look of it.
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Mac1airguns is where I got my kit from.
Btw I'm not sure what kind of paint you would use, but Timmy refinished my gun when the barrel needed re- soldered and it's not as durable as the original brass black or whatever finish they used.
I don't know if there's something better to use, but I would think Timmy at mac1airguns would use it.
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I'll very much need to look into paint / finish options. Will want something that will last / hold up and look good.
Since she's a keeper, she may not look "good" to others, but in my eyes. :)
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Tool found on Baker, will order that soon.
I as well remember Mac1 being a bit difficult to navigate an search for specific tings
does show a lot out of stock. I'll have to take a bit more time and just go thru page by page.
I would like to increase the power a bit in Old Blue. but, not fully sure which parts there would an would not do so.
As well, since I don't have the machinery, I'd have to make sure were all "bolt on" parts that do not require any machining.
I'm figuring the steriod parts will toughen her up as well dress her up a bit.
I'll look thru the kits a bit more an see if I can find / see a bit of improvement in the "guts" area
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Now... for you comment on a new 392... DO IT!
If you shop around you can find them for about $120-130.... Darn nice gun!
Just take some acetone (nail polish remover) on a Q-tip to the crown for the known over spray problem first.
that 392 hit the same or harder than the Blue Streak?
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I have been successful in making the 392 & later Blue Streaks hit harder, much harder than stock. The old Blues you can get them to hit a little harder. The steroid parts are just beefed parts that allow you to put in more then the recommended 8. The beefier parts won't wear out or bend and break like the factory parts when you go well beyond 8. Then he essentially puts a really weak valve spring in requiring you to cock for it to take air. I do the same thing, but on the 39x and later Blues (C9A) have a half cock. Wouldn't even call it a half cock you just lift the bolt handle and it does the half cock.
Now the reason it can be done on the 39x and C9A's is they have a removable cartridge valve. With the valve in hand it makes doing mods a whole lot easier. Either doing a ACP or a max power valve. Can increase or decrease volume in valve, bore the exhaust hole, grind the brass to angle the flow to exhaust, take up headspace in front of the valve where it meets the pump cup, etc. From here you could get some steroid parts and go well beyond the recommended 8. The last rifle I did for another member would do a full dump on 9, but was getting plenty of power on 8.
(http://i.imgur.com/JJFwrSx.jpg)
(http://i.imgur.com/74uQQgG.jpg) (http://imgur.com/74uQQgG)
As you can see adding the little piece of felt pad on the forearm took away .6 FPE, but makes pumping a little quieter.
I have numbers for my 392PA. Which was the first rifle I worked on, didn't get it as high as this C9A at first. https://www.gatewaytoairguns.org/GTA/index.php?topic=112378.msg1103512#msg1103512 (https://www.gatewaytoairguns.org/GTA/index.php?topic=112378.msg1103512#msg1103512)
But recently went back into her and touched some things up. I'll have to find them, but I believe I had them over 700 FPS as well.
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Once my chrono arrives I can then keep track an find out fps, well, after Old Blue gets fixed again.
Still lookin' 'round for the "guts" an parts to put on her
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You can make the part by grinding away on a socket. It's very easy I made one for the Dans and several for the older Crosman, that require 2 different size tools to remove both nuts. If you just resealed it a few years ago it's probably still good and that valve nut has come loose. When you pump it is the air coming straight out the barrel? If not and it just sounds like it's coming from somewhere take off the back end of the rifle removing hammer and all and the sound of releasing air should be clear. If it's a slow leak just listen of drop some oil down there onto the nut and you will see it bubbling around the nut.
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*nods*
I had replaced the guts 'mebbe 2 years 'go.
She was shootin' pretty good, kept a couple pumps in durin' storage.
Had her out one day, shot a few times, still shootin' good an hard. Put a couple pumps in to put away.
Few days later, got her back out.
When pumpin' it does nothing. Doesn't build air at all now.
I've not had the chance to get into her to see "where".
I jus' figure since gonna tear her down to find out the "why" & "how", may as well pick up "tough" "better" etc. parts for when I put her back together as well as make her look nice 'gain.
Already order'd the tool, figured it was a good investment an I'm guessin' it will prob be helpful with the 392 when I get that.
My 664x Crosman on the other hand, not sure what "tool" will be need'd for that. She still fires good, jus' need's to be torn down an clean'd up etc. an the same, since gonna have apart, why not make her hit harder an be tougher.
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That tool won't help on a modern 392. :'(
The early '90s 392P had a soldered in valve but after that is went to the Crosman cartridge valve.
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Like I was saying you can diagnose her just by pumping her. 2 year old seals should be good for another 30-40+ if you do your part with live and leaving a pump in her. Like I said, if you hear are coming straight out the barrel(or receiver if you cock the bolt) the valve stem is your culprit. If it sounds like it's leaking from somewhere it's the valve nut having came loose.
Now you said "when pumping it does nothing. It doesn't build air at all now". You mean on the downstroke you aren't getting any resistance? If that's the case something could be up with the check valve. If so the forearm will want to shoot opening because that air is pushing it open. If not you should definitely be hearing air either being pushed out with each pump or the sound of a slow leak.
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Didn't take it apart yet. Tool should be on it's way an e'en if can only use on the one, still "good" to have.
THAT bein' said...
Cocked it, pumped. Really, no resistance to very very little on the down stroke. When pullin' on the forearm it springs open on it's own.
I couldn't hear any air leaking, but really don't think much was getting in. Pumped it like that a few times & squeez'd the trigger, really didn't sound like much "poof" coming out an I doubt there was 'nuff to push a pellet thru.
So would seem the check valve as you were saying.
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Sure sounds like a check valve not seating to me....
I have had luck with an alcohol flush.
Boo-ya! Try researching that here!
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Yup, something is stuck and keeping your check valve open or it split. Who's kit did you use for the reseal last time? So, your pump cup is acting like the check valve. So when you go to open the arm that previous pump of air is pushing against pump cup and swinging your forearm open. Essentially you are putting 1 pump in and letting it out, putting 1 pump in letting it out, over and over again.
Since you say the pressure isn't building up. Something large is definitely in the way of the check valve. Do the iso alcohol flush, like Scott said, and follow up with oil. May do the trick.
Steps...Open arm up and put alcohol down the slot and push arm downward. Open up arm a little, but not too far. Cause it's gonna take a bit for the alcohol to get pass the pump cup's seal. After, a little bit open up arm slowly toward the slot and you will see if the alcohol made it pass the pump cup. If so, pump fast and hard which will attempt to dislodge whatever is in the way of check valve. Cock it and shoot it out. You may need to do this a couple times. If this works follow it up with oil. All this is for nothing if your check valve split or broke.
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I just got done reading on the alcohol flush.
The kit I got was from Mac1
I'm guessing it couldn't hurt to get a new cup as well as clean her up real good prior to installing the new one.
Once the tool arrives I can get it all apart an see if anything did split or break.
I mean, new parts can't "hurt" since the cup was the orig an wasn't replaced with the kit.
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Ok since I know you got Tim's kit with the white Teflon check valve. Did you remember to have the "X" up? Secondly, when you dropped the check valve in did you get something long to put on the top of check valve, then proceed to give it a decent tap with a hammer?
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I do remember doing that. Grant'd, it was Order date: 03/18/2015 so ya know, the memory don't always 'member it all.
but I do know after puttin' it in, it work'd quite well 'till this happened.
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The kit I got was from Mac1
I'm guessing it couldn't hurt to get a new cup as well as clean her up real good prior to installing the new one.
I mean, new parts can't "hurt" since the cup was the orig an wasn't replaced with the kit.
I am sorry... but... WHAT?
(https://media.giphy.com/media/H315tBsDtcGCk/200.gif)
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I just read right past that. Good eye Scott! I've had pump cups still soft and looking great and tried reusing because of this. All those soft old pump cups look good, but when you remove from tube it will easily slide out. Same if you try putting back in, it will go in effortlessly. A new cup you will need to work in the edge to get it inside the tube. Though you are getting the forearm to opening up quickly on its own. I bet if you wait a minute that air, between the cup and valve face, will escape pass the cup and it will open up as it should.
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Took the front end apart today. I had a dish with the old parts from when I got the Mac1 kit, not sure why I had them.... but they were there. The cup in the dish was torn, so the cup did get replaced. The cup doesn't slide out / in super easy, but really doesn't need much "help" to do so. I didn't have anything to inject alcohol in to pump up that way an not much really went in the hole. Still doing the same basic thing, after one pump, forearm kicks out then no resistance on a pump. Dry fire does produce a small puff of air.
I should have the tool I ordered from um, Baker or sumtin' arrive soon.
I'm guessing a new kit and good cleaning once taken apart should bring her back to life.
I'm kinda looking at the adjustable pump as mine is the non-adjustable.
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New to this thread. But when it doesn't pump up, and you get no resistance when pumping, that says 'pump cup' to me. Maybe if the check valve AND the exhaust valve are shot and not resisting air flow to the barrel, then you have to deal with the valve internals. But pump cup is my first guess, particularly since yours is original from the last century.
If you have the press in kind of pump cup, sometimes even a new one won't push air into the compression chamber. But you can put a thin washer behind the cup and it 'poofs' it out enough to push air.
Oh, and the adjustable pump cup can only make a small difference in stroke, may 1/8"-1/4", but that small difference can make a big difference in how much air you push into the compression chamber. Fewer pumps to get the same output.
My $0.002
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When I had the front end apart & looked in the dish with the old parts, it was a new cup. Did not off a lot of resistance to get it in or out.
The front end is a lot faster than the guts.
Startin' with a front end rebuild with a nice blued plug an adjustable piston seems a good start.