# Bostich air stapler T50S4 won't fire



## packrod4wt (Apr 3, 2011)

I have a lightly used T50S4 that won't fire. When aired up, and safety depressed, the trigger only makes a popping noise with no driver action. I have it apart, none of the parts appear to be broken or worn. I had it rebuilt once at a shop, and now it is back up to the same problems. Unfortunately I don't recall what repair the shop performed. Any suggestions, like buy Hitachi, etc.


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## Ron6519 (Mar 28, 2007)

packrod4wt said:


> I have a lightly used T50S4 that won't fire. When aired up, and safety depressed, the trigger only makes a popping noise with no driver action. I have it apart, none of the parts appear to be broken or worn. I had it rebuilt once at a shop, and now it is back up to the same problems. Unfortunately I don't recall what repair the shop performed. Any suggestions, like buy Hitachi, etc.


If you try another air gun, does it work?
Do you have an independent device to measure the air pressure coming out of the compressor? 
Ron


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## fybountyhunter (Apr 5, 2011)

maybe putting some light oil in the gun may help....


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## Ron6519 (Mar 28, 2007)

fybountyhunter said:


> maybe putting some light oil in the gun may help....


It would need to be pneumatic tool oil.
Ron


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## packrod4wt (Apr 3, 2011)

Thanks for the reply, air pressure was adequate, in fact I tried it with two different compressors. I'm just being cheap, don't want to invest $ in an older gun if the problem keeps repeating. It is a 16 ga., 1/2" crown construction stapler, most new construction staplers I believe have gone to 7/16" crown and the staples are cheaper as they are more common.


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## packrod4wt (Apr 3, 2011)

Thanks Ron. I did oil the stapler (I used Senco gun oil, not sure if this is a problem), and when I took the gun apart all the sliding parts seemed to be well lubricated. I'll go lube it again and re-assemble it...I just don't want to throw parts ($) in it when I don't understand the problem yet.


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## dyutechie (Apr 21, 2011)

The trigger valve may need to be rebuilt with the correct internal o-ring (flat on one side and beveled on the other) if you can find one or just replace the entire valve with a new one. I tried rebuilding mine with a 25 cents o-ring because the OEM o-ring seal is not available. It stopped the leak but is exhibiting the same symptoms as yours. It looks like I will have to replace the entire valve (about $20).


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