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Thread: Crosman Town & Country 107

  1. #61
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    Quote Originally Posted by --ped-- View Post
    all the piston heads I have are the same as yours Louis and as you've seen this type are rebuildable but usually they were rebuilt by the service centres(you can get them from JG on an exchange basis still)
    is the rod adjusted correctly and these seals are designed to squeeze a bit on opening and expand when pumped so they sealed to the tube
    how much more clearance do you need can you shave a bit off the piston pivot block so the lever opens a touch more
    on one of my 140's and a Sheridan I found I had to slot the breeth hole a fraction when fitting upgraded pistons
    Good ideas. I will check later re the clearance.
    Do you know if the rod can be turned into the piston pivot block?
    This would be the logical way to adjust the length of the rod?
    Well, the answer lies at home hehe.

  2. #62
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    I’m mixing threads from the other forum but you said your pump arm was welded to probably put on the new pump cup? If you are now finding that it was not adjusted correctly he may have given up? It may be why your rifle is in such good shape, it wasn’t used after that? I’ve seen that with other vintage rifles, sometimes the ones in excellent shape broke and they were never fixed? Good thing is this is a easy fix, I bought one from Rick for a Crosman 101 that had a leather pump seal. Worked great and was not much money. I like you wanted to keep the original but in the end I used the new one cause I would be the only one that would know anyway.

  3. #63
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    Quote Originally Posted by 45flint View Post
    I’m mixing threads from the other forum but you said your pump arm was welded to probably put on the new pump cup? If you are now finding that it was not adjusted correctly he may have given up? It may be why your rifle is in such good shape, it wasn’t used after that? I’ve seen that with other vintage rifles, sometimes the ones in excellent shape broke and they were never fixed? Good thing is this is a easy fix, I bought one from Rick for a Crosman 101 that had a leather pump seal. Worked great and was not much money. I like you wanted to keep the original but in the end I used the new one cause I would be the only one that would know anyway.
    Yes I asked for Rick Willnecker's advice and he says part of my pump rod comes off a 1400.
    I don't really mind tbh, as long as it works (as you point out).
    Luckily, this rod is easy to adjust in length. Pfew.
    It took a few attempts to get the length just right.
    Now the cup clears the "breathing hole".
    However, I'm not there yet...
    The gun is very low on power (about 3.5 ft/lbs with 8 pumps. I've tried 15 pumps, the pumping is way too easy - 4 ft/lbs).
    Hmmm.
    It doesn't seem to be leaking. But I can't be sure. I am sure that the new seals are fitted correctly in the compression chamber. I've lubed them with a bit of silicon grease.
    I didn't bang the brass nut all the way down onto the pump cup base; I left a bit of space to make it easier to replace the cup next time. I can't see how this would cause low power though.
    One thing that struck me, is that the check valve spring in Rick's seal kit is about 1 cm longer than the one that was in the gun.
    The gun now contains Rick's spring.
    Perhaps the check valve cannot open properly with this stronger spring?
    My 108 is perfect though, and Rick resealed that for me a few months ago; I'm sure he used this same spring.
    And I don't think that the 108's internals are any different from the 107?
    Hmmmmmmm

    Any ideas?


  4. #64
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    Louis, if you left the brass retainer piece sticking out proud of the pump cup, then you've got excess 'dead space' in front of the piston cup which means the full gulp of air for each pump is not going into the valve chamber. Either pressing it all the way on or cutting it flush with the front of the cup will remedy this (also explains why your cup didn't clear the breathing hole with lever opened all the way: your overall piston head assembly is longer than normal). Obviously you'll need to re-adjust the rod length to compensate, so as to have the piston bottom out against the valve again.

    Don R.

  5. #65
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    Quote Originally Posted by draitzer View Post
    Louis, if you left the brass retainer piece sticking out proud of the pump cup, then you've got excess 'dead space' in front of the piston cup which means the full gulp of air for each pump is not going into the valve chamber. Either pressing it all the way on or cutting it flush with the front of the cup will remedy this (also explains why your cup didn't clear the breathing hole with lever opened all the way: your overall piston head assembly is longer than normal). Obviously you'll need to re-adjust the rod length to compensate, so as to have the piston bottom out against the valve again.

    Don R.
    I think Don’s got it. I bet it’s your pump cup? Also in not tapping down the brass collar firmly, air may be escaping through the cup? One way to see if it’s the cup let the charge you are getting stand overnight if it holds then you are not getting the air in? Pump cup and adjustment? But I’m a rookie, so what do I know?
    Last edited by 45flint; 15-12-2018 at 09:21 PM.

  6. #66
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    I would agree that it is the piston head leaking air past on the compression stroke and would press the brass collar on further
    as it's not a genuine piston but a later one I'd if all else fails put an o ring piston in it

  7. #67
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    Pfew, I am getting there. 5,5 ft/lbs with 8 pumps.

    @45flint, pumping the gun up and leaving overnight was a good idea. It had lost all pressure this morning.

    I had to dis- and reassemble the gun a couple of times to solve a few issues.

    One was the brass part holding the pump cup in place - it is now all the way down. The pump cup edge still doesn't protrude though; the alu base of the pump head and the brass part around it stick out a tiny little bit. I'm not sure whether this is normal or not. I compared the "height" of the new pump cup with the old one: it's the same. But maybe the original cup was higher?

    Then the exhaust body gasket. It wasn't on the exhaust body anymore. The groove in the exhaust body to hold the gasket is quite shallow. And the gasket isn't tight like an o-ring. The fact that it wasn't in place, explains why the rifle lost pressure overnight.

    Then the check valve spring. I'm not sure yet which works best: the short one that was in the gun, or the longer, new one in Rick's seal kit.
    I think the latter. It's in the gun now. The weaker spring might not shut the check valve well enough? Or is the stronger check valve spring causing the check valve to be too difficult to open for the air to flow into the valve chamber...? But then the air pressure inside the valve chamber is probably stronger than the spring. Will have to test.

    5,5 ft/lbs is not that fantastic, but it's something. It's 550 ft/s with 8.44 gr JSB's.
    I also cleaned the barrel - that wasn't a bad idea!

    I hope to get to about 8 ft/lbs, maybe I need to work on the bolt. Ped you wrote about lapping the bolt. I will need to find out what this means. Is it adding lead on the bolt head, in order to improve its fit in the barrel? Another option would be to make a groove on the bolt, for it to accept and o-ring? This would be a bad idea on the originality front though...

    An o-ring pump head would be a great idea, to test the difference. The problem might still be the cup not sealing well enough.
    A hint towards this theory is that pumping becomes harder up to 8 or 9 pumps, but then it's not that much more difficult to go 12 pumps, and the velocity increase is marginal. Maybe the pump is then simply not coping with the pressure, and leaking air - without me hearing it.



    The two different check valve springs



    And lastly, Christmas is coming...

    Last edited by jirushi; 16-12-2018 at 03:41 PM.

  8. #68
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    Quote Originally Posted by draitzer View Post
    Louis, if you left the brass retainer piece sticking out proud of the pump cup, then you've got excess 'dead space' in front of the piston cup which means the full gulp of air for each pump is not going into the valve chamber. Either pressing it all the way on or cutting it flush with the front of the cup will remedy this (also explains why your cup didn't clear the breathing hole with lever opened all the way: your overall piston head assembly is longer than normal). Obviously you'll need to re-adjust the rod length to compensate, so as to have the piston bottom out against the valve again.

    Don R.
    Hi Don R., thank you for your advice. Cutting the alu base and brass retainer piece flush might be a good idea! After pressing it all the way on, the pump cup still isn't protruding. The breahting hole is clear now though.

  9. #69
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    “An o-ring pump head would be a great idea, to test the difference. The problem might still be the cup not sealing well enough. A hint towards this theory is that pumping becomes harder up to 8 or 9 pumps, but then it's not that much more difficult to go 12 pumps, and the velocity increase is marginal. Maybe the pump is then simply not coping with the pressure, and leaking air - without me hearing it. “

    That doesn’t sound right, should be harder to pump with each stroke?

  10. #70
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    Quote Originally Posted by 45flint View Post
    Awesome! Interesting that they must have just changed to that type when they made yours? Or possibly the 1949 dating of the Kringle paint T&C sighted 101 is earlier than we thought? I know mine was brass on both parts and screwed in. Glad you got it apart.

    Looks like DT Fletcher on another forum says that this was not original, but a replacement? Would make sense given my 1949 101? He says it’s not rebuildable but can’t see why not now that you have it apart?
    Most anything is rebuildable, given enough time, effort, and the right parts. Back in the day, these pump assemblies were never rebuilt for the simple reason that Crosman didn't sell the individual pump cups. That was the basis of my statement. Today, with replacement pump cups, they can. Which, clearly, is (good) news to me. Same with the old 150/160/180 etc model exhaust valves, until Rick started sourcing the proper seals, these valves were considered non-rebuildable, but, today they are. Fortunately, I tended to keep these valves and had a coffee can of 'em which I proceeded to rebuild with parts from Rick.

    Like I said on the other forum, I would never rebuild one of these guns with that small check valve seat: it's unreliable and was replaced in production by Crosman with the large version.

    Pump adjustment: Per Crosman factory engineering, the pump is properly adjusted when the pump head presses firm against the air chamber and then just enough more so that the pump rod "over-toggles" which forces the pump head against the air chamber and hold the pump arm firmly in place. No other adjustment is (factory) acceptable.

    I never worried too much about the air hole. The pump head is not very effective when run in reverse and unless the pump arm is hard to open up, you probably don't have a air supply problem. In other words, don't use the air hole to determine pump arm adjustment.

    Didn't see what oil you're using. Most oils and all oils intended for spring guns, are not acceptable. I presume you're using Crosman oil, or MAC-1 Secret Sauce (I know the secret, if you're looking for a local source) or .....?
    Last edited by DT Fletcher; 17-12-2018 at 07:21 AM.

  11. #71
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    the last one of those type valves and inlets I resealed was a 105 which had rock hard seals -not having a replacement set I milled the hard seal out to take a poly 2240 co2 seal on both stem and inlet(I use the same poly seal on the older dan inlets)
    instead of the flat exhaust body seal I use an o ring ,did you correctly align the exhaust body with the port
    lapping the probe is just like doing a cylinder head valve -bit of paste and twiddle till you see an un broken line of contact on both parts
    I have a 140 oring piston head conversion in stock but I only do them on an exchange basis

  12. #72
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    Quote Originally Posted by DT Fletcher View Post
    Most anything is rebuildable, given enough time, effort, and the right parts. Back in the day, these pump assemblies were never rebuilt for the simple reason that Crosman didn't sell the individual pump cups. That was the basis of my statement. Today, with replacement pump cups, they can. Which, clearly, is (good) news to me. Same with the old 150/160/180 etc model exhaust valves, until Rick started sourcing the proper seals, these valves were considered non-rebuildable, but, today they are. Fortunately, I tended to keep these valves and had a coffee can of 'em which I proceeded to rebuild with parts from Rick.

    Like I said on the other forum, I would never rebuild one of these guns with that small check valve seat: it's unreliable and was replaced in production by Crosman with the large version.

    Pump adjustment: Per Crosman factory engineering, the pump is properly adjusted when the pump head presses firm against the air chamber and then just enough more so that the pump rod "over-toggles" which forces the pump head against the air chamber and hold the pump arm firmly in place. No other adjustment is (factory) acceptable.

    I never worried too much about the air hole. The pump head is not very effective when run in reverse and unless the pump arm is hard to open up, you probably don't have a air supply problem. In other words, don't use the air hole to determine pump arm adjustment.

    Didn't see what oil you're using. Most oils and all oils intended for spring guns, are not acceptable. I presume you're using Crosman oil, or MAC-1 Secret Sauce (I know the secret, if you're looking for a local source) or .....?
    Hi DT, thank you kindly for all the interesting info and thoughts.
    Especially the pump adjustment info is very interesting - I bet the power issue of my 107 is partly due to wrong adjustment. I think I've over adjusted, meaning that the rod is screwed into the piston pivot block too much. This explains why the forearm drops down easily now.

    Then the small check valve base. Will have a look on the JG airguns website if they sell the larger version.

    The gun has held air overnight.

    I used silicone grease on the seals. And a tiny bit of moly grease on the metal parts of the pump rod that make contact with the tube wall.
    Do you think that this would cause issues? I have Pellgun oil, no "secret sauce".

    @ Ped, I think the exhaust body is aligned properly; the blind hole on the exhaust body (see drawing) is aligned with the hole in the tube.
    Good idea to use an o-ring in lieu of the flat exhaust valve body seal.
    The seal seems to be working now though.
    What kind of paste do you use for lapping?


  13. #73
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    valve grinding compound Louis ,use the fine one not the coarse

  14. #74
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    "I used silicone grease on the seals. And a tiny bit of moly grease on the metal parts of the pump rod that make contact with the tube wall. Do you think that this would cause issues? I have Pellgun oil, no "secret sauce". "

    Silicone grease is going to attract dirt and grit, I'm assuming. Moly grease? No idea. The question is: is it compatible with hydraulic systems?

    The problem is that the lubes used will invariably end up on the seals, so, that lube needs to be fully compatible. MAC-1 did their work in finding a better lube than Crosman (which tends to gum up) and they came up with Secret Sauce. I've let out the "secret" a number of times so no big deal; it's heavy weight motorcycle fork oil. 50 wt, if memory serves. Can't recall the brand they used but might have been Bel-Ray. It's pretty certain that any high quality fork oil is going to be okay.

    I made the effort to use the flat washer for the exhaust valve, instead of an O-ring. As I recall, the flat washer made it easier to get the exhaust port properly aligned with the barrel inlet.

    If you go for a replacement pump rod, again as best as I can recall, the 101 pump rod is the same thing. Pretty wild how the previous repair actually welded the new pump head on the old one. Pretty sure it's a first for me. Your rebuilding the previously unrebuildable pump head being another first.... for me anyways.

    These guns are great fun to work on and even more fun to shoot.

  15. #75
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    Had to think a bit about precisely why o-rings aren't the best choice to replace the stock square-section seal. Note the positioning indent on the exhaust valve body; this is the shallow hole in the body that can be seen through the hole in the compression tube. These holes when perfectly aligned mean that the exhaust port is perfectly aligned at the same time. So, when installing the exhaust body, you want to place a rod of the precise diameter that fits these holes, then, with that positioning rod in place, fully tighten the exhaust nut, without the exhaust body moving at all. This usually doesn't work with an o-ring... as I recall.

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