397PA Puffs air out of barrel when pumped ?

[linoww]

I got it used and  eventually it wouldn't pump up. I took the back end apart and cleaned all of the old cruddy oil off of the valve and then it was back shooting. Now when I pump it up it puffs air out of the barrel the first part of the stroke. If i pump fast not as much but if you go slow it will just puff all the air out. It is shooting fair but something isn't right.Velocity at 8 pumps its 675 with Crosman Premier Lites.

George

[Mr.Bojangles]

Id hafta say the valve is leaking. A new valve or repair parts are most likely in order. Im sure theyre available through crosman, and i dont think theyre very expensive.

http://www.crosman.com/cs/manuals

[limbshaker]

You need a new exhaust valve seal, or at least take the old one out and try cleaning it up.


That should get you started. If you have to order parts, get a whole valve from Crosman. They are around $14 complete and ready to drop in. If your valve is like the one in my video, the part number is:  397B032

[linoww]

Thanks.is it easy to take the valve assembly apart or should I just order the whole thing?nevermind,watched the video.
How can you improve the valve or hammer to be better or mot dump all the air?I thought I heard there was a simple way to do this.

[linoww]

Took it apart and cleaned it.its still acting the same.all parts appear to be fine.

[Roadworthy]

Just a thought, could the hammer spring be weak or broken?

[oldnamvet]

I had exactly the same situation with a 392.  I ordered the valve assembly from Crosman, got it a week later, and put it in.  Everything works well now, no leakage when pumping.

[Slavia]

Try cocking it before you pump.  Maybe somebody replaced the hammer spring with something that holds the exhaust valve open.