Because I have a large collection of airguns some of them don’t get much exercise as they sit for a long period of time in the storage cabinets. A few months ago, I started to get them out for shooting sessions.
This is when I discovered that my QB Chief was leaking and the ensuing process to try to repair it by machining new valve stems was documented on the forum at the end of July 2022. Accumulating failures, I finally ended up buying a stem with a Delrin head from Wes. I received it at the beginning of August and that solved the leaking problem.
I followed the advice of Killercrow and ordered several feet of Delrin in two sizes (1/2” and 3/8”) from Aircraft Spruce thinking that with the number of vintage airguns I have it might be useful. As a practice, I made a spare stem for the QB using the material I received. Since the QB Chief was repaired and I didn’t want to disassemble it again, my part has not been tested but I am fairly confident that it should work. For now, the extra part is stored with the QB Chief documentation.
I continued to shoot my CO2 vintage airguns and, at the end of September, I discovered that both my Crosman 622 were having some problems. One was leaking through the barrel and not indexing properly then the other was not leaking but needed a lot of torque to get enough pressure to pierce the CO2 cartridge. This made me think of the possibility that the valve was backing off and needed to be pinned. Both of them were repaired.
I didn’t know yet but that was the beginning of my marathon.
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The next ones that came up were a pairs of Crosman Mark I at the beginning of October. I repaired both piercing caps and resealed both pistols. I even experimented with the valve stems, I made one with a solid head of Delrin and the other with an aluminum head and a Delrin insert.
After that I worked on my Ampell Acro I. It was not leaking but I had fabricated, in the past, a homemade seal for the CO2 cartridge because when I bought it at a flea market that part was missing. This is a very simple airgun and I was curious to see how the valve was made. Since I took it apart to look inside, I made new seals.
From my pair of Crosman 38T, one was leaking so I resealed it and machined a new valve seat from Delrin.
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My Crosman SA6 had a slow leak through the barrel and I didn’t have the service manual for that model so I was a bit weary of messing up things. Fortunately I found enough information on the Web to give me confidence that I should be able to repair it. The problem with those old airguns is to separate components stuck together. It also happened with the Mark I and the Acro I. The valve stem of the SA6 is different the others I have seen because the shaft is sticking at both ends of the sealing head. One end is hit by the hammer and the other is the piercing tip. I was able to make a new one and it worked.
When looking for other vintage models in my cabinet, I saw that the gauge of one of my Crosman 1701P Silhouette was at zero. The disassembly showed that the plastic head of the valve stem was shattered. A new one from Delrin was made and the pistol repressurized.
In the process of troubleshooting the leak of the Silhouette I overworked my Bull handpump and I thought I had blown an o-ring. This required a teardown, cleaning, lubrication and reassembly.
It is now mid-October and I am back at my vintage airguns testing the S&W 78G. By now it should be expected, same story of an airgun with a slow leak through the barrel and it became a candidate for a new valve stem.
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My 1377 and my 2289 were still having air in them when I got them out of storage and, basically, I should have left them alone. It was past mid-October but the weather was still nice and I thought I could probably work on another project before shutting down my garage shop for the Winter. It was probably a bit too ambitious because, until this point in time, I only made valve stems for existing valves and now I was looking at making a flat top valve and piston. It kept me busy until the end of October but didn’t end as well as I would have wished.
To overcome my frustration, I tackled a simple project that I knew would work and made several little screws to replace the original 4-48 breech screw of the Crosman 13XX and 22XX. This was at the end of October.
At the beginning of November, being done with the vintage airguns, I went back to checking my PCPs and found that my Brocock Grand Prix Super 6 was leaking from the filling nozzle. For this one I didn’t dig very far and just removed the nozzle to fix what was wrong.
Now that I have completed all that work I have the dilemma of deciding if I should write individual posts covering these repairs or just forget about it. Writing the posts takes a lot of time (sometime nearly as much as doing the job) and I am wondering if it is worthwhile. I am not sure if I am boring people because my posts are fairly long or if others can find something useful for them.
After pondering the question, I finally got my answer.
When I am looking for information to help me with my repairs, I am happy to find that some people took the time to document their experience and provided some bits and pieces on different aspects of a disassembly or reassembly procedure.
In return, what I did or find during my repairs could provide bits and pieces useful to other people looking for specific information and I feel that I have some responsibility in sharing it.
Once I have posted all the individual repairs, I am planning to add the corresponding links to this one.
R-Gun Pete
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