benjamin 347 trigger type

[ped]

i've just recently got a 347 to restore but it came with a few parts missing-complete trigger assembly, bolt and some screws
there's two types of trigger listed but i haven't been able to find out when the triggers changed so was hoping someone may have an idea when the change over occurred
the serial on mine is T347xxx and from the serial no dating chart is a 1979 model with chequered stock but has a tootsie roll pump arm the same as my 312 which may not be original
ped

[longhunter]

Check with dennis baker, baker airguns.

[ped]

i've now found that it's the later type
just need to get it to seal now-strip the valve and rebuild seals fine shoot it (using the trigger unit off my 312)and it vents out of the barrel,strip the valve and rebuild and it seals shoot it and it vents out of the barrel
i've also tried using a disco stem a 22xx stem with the piercing pin cut off a bluestreak stem and it's doing my head in

[longhunter]

check the valve stem for wobble, in the base. it could be that your valve is worn. have you tried cocking the gun, before pumping it? you could also have a worn out valve spring. it's not strong enough to seal the valve. that's why it seals fine, when you put it together, but, won't seal after it gets hit with the hammer.

[ped]

cheers scott had a bit of spare time and i think i've sussed it to a degree found four issues
1+2 valve seal has hardened and it's not at 90* to the shaft
3 valve exhaust body has a little play in it but not really excessive and had a faint scratch in it
4 valve spring ends weren't ground parallel to each other
i refaced the seal 90* to the shaft in the lathe both sides plus cleaned up the seal face on the exhaust body
the spring i reground the ends so it pushed the stem square and added a couple of extra shim washers to add preloade to the spring
now she pumps up and shoots i do have a faint leak on the stem seal so i'll replace all the valve internals i think