Hello everyone. I recently acquired a Crosman 101 in very good shape. It was advertised as "holds air forever" etc. It did wok fine for about a week but now will not fire. Prior to this issue, it would only hold air when the gun is cocked, as per deigned. Without the gun being cocked, you could hear the air escaping with each pump. It no longer does that. It seems to hold pressure when pumping both cocked and un-cocked. I can feel the resistance in the pump arm. The trigger releases the hammer and the hammer seems to be hitting the valve stem. I removed the hammer spring nut with a small spanner that I have for camera repair. The body lock nut is further down the receiver and I cannot reach it. I ordered the tool that is needed to remove this and until i receive it, I've been researching disassembly and what might be causing this, Thoughts? Is there anything else I should be looking at? I'm pretty handy but don't have all the tools necessary for major repairs so any help would be greatly appreciated. Thanks-Jimmy Z
Help with Crosman 101
- Thread starter Jimmy-Z
- Start date
Thanks for the response. I did try Alphabet org at the pump cup and the rear of the valve. I don't think its a pressure issue. It feels like it's more of a failure to release the pressure. I'm not 100% sure and guess I won't know until I can remove the valve.
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Thanks. That's the video I've been using for reference. I'm stuck at removing the second lock nut. I made a tool that i thought would be strong enough to break the nut free but my skills were not up to par! Waiting to receive the one in the mail. I'm a little concerned that there is pressure in the gun not being released.
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So it's pumped and when you cock it and pull the trigger does it release the hammer and (NOT) knock open the valve or is the sear just not catching the hammer?
Its actually recommended to leave 1 or 2 pumps in the gun when stored.
Its actually recommended to leave 1 or 2 pumps in the gun when stored.
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The trigger is releasing the hammer. I was able to unscrew the hammer plug and I can see what appears to be the exhaust valve stem. I placed a couple drops of Alphabet org there to see if it would do anything, Also, I figured that it if the gun was cocked and had air, I might be able to place a punch on it and tap with a hammer to release air. It didn't work and I didn't want to hit it too hard and do damage. Maybe it's not pushing air into the valve and cocking it but there seems to be a decent amount of pressure on the cocking arm. The weird thing is that with the gun not cocked, the pump of the arm used to give an audible release of air. (The gun has to be cocked to hold air) That is no longer happening.
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Thanks again. I think I need to get that valve out to see what the heck is going on. It looks like a pretty simple design but I can't see what's happening until I break it down a little further. I thought maybe I was missing an easy fix but I'll need to dig in further.
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Broken valve spring. On mine it is brass, and still in good shape but if it seems to be holding air and not releasing it it is a place to start. You will need that long spanner. I built one that "barely" worked. When I ordered my rebuild kit from Baker Air I splurged on the spanner- worth every cent. Unfortunately I cannot remove the pump cup on mine and that is what is not working. It has been soaking in penetrating oil for a week and still no go. Once we see some warmer temps I'm going to try to take some heat to it. The Baker kit is nice- but the directions leave a lot to be desired. No real explanation of what gets replaced with what. A lot of trial and error on my part and I still don't have a gun that works. I have tracked it down to the pump cup because that is the only remaining seal that has not been replaced (I have the old style double leather washer ring on mine and have no clue how to replace it with the cup yet). The other nice thing is that Baker will rebuild the gun for you if all else fails, and deduct the price of the kit from the rebuild price. Best of luck!
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Good info. Baker Airguns is where I ordered the longer spanner from. I made one from a piece of conduit but the points weren't strong enough to turn without bending. I'll see what I can do when it arrives and to your point, if all else fails, I'll sent it out for repair.
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I received the spanner tool from Dennis Baker and went to work on the gun to see what I could find. The second lock nut seemed very tight and tough to remove even with the new tool. Upon loosening it up, the gun suddenly let out a pop through the barrel and the nut then came out smoothly. Like I suspected, there was stored energy in the valve. However, I couldn't find any obvious culprits as to why the valve locked up. I cleaned and polished all the moving parts, made a new urethane seal for the front valve and lubed the rest of the parts. I put everything back together and it seems to be working fine now. I never chronographed it prior to the issue, so I don't know if it's shooting any differently as far as velocity. It does seem quite powerful and is definitely holding air and working correctly. I guess it will be a mystery as to what actually happened. 
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Glad you got is sorted.
Like you said, sounds like your rifle had valve lock. It is caused by a couple of things on a pumper.
1. Over pumping- Pressure in the valve chamber will build up higher than normal, preventing the hammer from opening the valve when released.
2. Not dumping all the air from valve chamber when hammer is released. So, every time you pump it and fire, a little extra air stays in the valve after each shot, eventually this pressure builds up and could lead to valve lock.
The latter issue makes sense in your case. You stated that in the beginning your rifle would only hold air upon cocking the hammer first. Eventually, cocking the hammer was not necessary. That's because the residual air pressure was higher than the slight preload of the hammer spring, thus holding the valve closed and preventing it from blowing out the barrel as before.
Here's a scenario to help further explain.
Say a rifle only capable of dumping 7 pumps is charged with eight or more pumps, then a small amount of air will be left in the chamber. If it is not emptied at that point and the rifle is again charged with eight or more pumps, then more residual air is left in the valve chamber. If this is repeated several times then the pressure can eventually build up high enough to cause valve lock. Which is what may have happened in your case.
Smacking the back of the hammer knob with a rubber mallet or block of wood is a quick fix.(make sure it is not cocked or you may snap the sear off the trigger)
Sometimes more pumps does not equal higher velocity. Finding out how many pumps your particular rifle will dump in one shot is a quick way to prevent issues like this.
Like you said, sounds like your rifle had valve lock. It is caused by a couple of things on a pumper.
1. Over pumping- Pressure in the valve chamber will build up higher than normal, preventing the hammer from opening the valve when released.
2. Not dumping all the air from valve chamber when hammer is released. So, every time you pump it and fire, a little extra air stays in the valve after each shot, eventually this pressure builds up and could lead to valve lock.
The latter issue makes sense in your case. You stated that in the beginning your rifle would only hold air upon cocking the hammer first. Eventually, cocking the hammer was not necessary. That's because the residual air pressure was higher than the slight preload of the hammer spring, thus holding the valve closed and preventing it from blowing out the barrel as before.
Here's a scenario to help further explain.
Say a rifle only capable of dumping 7 pumps is charged with eight or more pumps, then a small amount of air will be left in the chamber. If it is not emptied at that point and the rifle is again charged with eight or more pumps, then more residual air is left in the valve chamber. If this is repeated several times then the pressure can eventually build up high enough to cause valve lock. Which is what may have happened in your case.
Smacking the back of the hammer knob with a rubber mallet or block of wood is a quick fix.(make sure it is not cocked or you may snap the sear off the trigger)
Sometimes more pumps does not equal higher velocity. Finding out how many pumps your particular rifle will dump in one shot is a quick way to prevent issues like this.
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Wadcutter-This is some great info. Thanks for taking the time to jot it all down. I think you hit the nail on the head as to the issue I was experiencing.
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