392 linkage (popping sound when pumping)

[35 shooter]

I have a 392 that i’m Pretty sure needs a seal kit put in, but it’s also making a popping sound in the forearm when pumping?
Sometimes it sounds like it’s coming from the arm that has the large press in pin that attatches to the billet. Other times it seems to come from the very end of the pump tube where the roll pins hold the pump arm.

This has happened after about 15,000 pellets through it since new about 3 years ago.
I can put 1 pump in and shake it hard, and the pump handle will fall away a bit from the pump tube.
I had to reseal this gun within a year of buying it new and found the culprit to be the seal on the valve stem, but went ahead with new pump cup and all the valve seals too.

I have’nt ordered a seal kit yet nor taken it down... just wondering what the popping sound is, and do I most likely need a new pump linkage, or even the arm that attatches to the billet down in the forearm?

Pretty sure i’m Going to need a new valve stem, and maybe the pump cup, but the popping in the billet or linkage is a new one on me.
Any ideas on what’s making the popping sound?

[longhunter]

Look at the roll pin, that holds the pump arm to the end plug. The "slit" that runs the length of the roll pin should face the muzzle. If it faces the breach, that's the most likely cause of the clicking.
  As far as the pump arm dropping, do you have the retainer spring behind the lever link ? If not, that's why the pump arm drops.

[TerryM]

  I have an old Crosman 108 Town & Country that pops when pumped.  The rivet holding the pump arm to the linkage turns a bit, causing the popping sound.  It's very annoying.

[Tack Driver 10]

I have a 392 that i’m Pretty sure needs a seal kit put in, but it’s also making a popping sound in the forearm when pumping?
Sometimes it sounds like it’s coming from the arm that has the large press in pin that attatches to the billet. Other times it seems to come from the very end of the pump tube where the roll pins hold the pump arm.

This has happened after about 15,000 pellets through it since new about 3 years ago.
I can put 1 pump in and shake it hard, and the pump handle will fall away a bit from the pump tube.
I had to reseal this gun within a year of buying it new and found the culprit to be the seal on the valve stem, but went ahead with new pump cup and all the valve seals too.

I have’nt ordered a seal kit yet nor taken it down... just wondering what the popping sound is, and do I most likely need a new pump linkage, or even the arm that attatches to the billet down in the forearm?

Pretty sure i’m Going to need a new valve stem, and maybe the pump cup, but the popping in the billet or linkage is a new one on me.
Any ideas on what’s making the popping sound?

I have a recently acquired Benjamin 312 with a similar problem.
It made a popping/snapping sound when the pump arm was about half way closed.
The rivet on the pump arm was the obvious culprit as seen in the picture.

[35 shooter]

Look at the roll pin, that holds the pump arm to the end plug. The "slit" that runs the length of the roll pin should face the muzzle. If it faces the breach, that's the most likely cause of the clicking.
  As far as the pump arm dropping, do you have the retainer spring behind the lever link ? If not, that's why the pump arm drops.

I may have learned something here... I had no idea it mattered which way the slit in the roll pin faced.
I’ll check that for sure.....Thanks!

[35 shooter]

Thanks Terry and Ron,

I was suspecting the big rivet holding the link arm that goes to the billet.
I haven’t noticed it moving at all when pumping, but that still may be it.
I’ll check it again along with the roll pin.

Does that rivet drive in and out with a punch, or does it have to be pressed out?

[35 shooter]

Ok, I drove out the roll pin and turned the slit toward the muzzle as was suggested... it still pops when pumping.

I watched the big rivet that holds the pump linkage arm to the billet in the forearm under a bright light. It did jump a bit when the pump arm was about half way down. I could tell this time it was turning just a bit under pressure.
The retainer spring in the billet behind the linkage arm is still in place.

Do I just replace that rivet, or will the hole in the billet and linkage arm have to be drilled out to a larger size to account for wear?
Again, does that rivet press out with a special tool, or can it be tapped or driven out?

I was’nt paying attention when I posted this thread... should have put it under the Crosman forum.

[Tack Driver 10]

Ok, I drove out the roll pin and turned the slit toward the muzzle as was suggested... it still pops when pumping.

I watched the big rivet that holds the pump linkage arm to the billet in the forearm under a bright light. It did jump a bit when the pump arm was about half way down. I could tell this time it was turning just a bit under pressure.
The retainer spring in the billet behind the linkage arm is still in place.

Do I just replace that rivet, or will the hole in the billet and linkage arm have to be drilled out to a larger size to account for wear?
Again, does that rivet press out with a special tool, or can it be tapped or driven out?

I was’nt paying attention when I posted this thread... should have put it under the Crosman forum.

May be best to get a new pump arm or a billet steroid arm from Mac1?

[35 shooter]

Ok, I drove out the roll pin and turned the slit toward the muzzle as was suggested... it still pops when pumping.

I watched the big rivet that holds the pump linkage arm to the billet in the forearm under a bright light. It did jump a bit when the pump arm was about half way down. I could tell this time it was turning just a bit under pressure.
The retainer spring in the billet behind the linkage arm is still in place.

Do I just replace that rivet, or will the hole in the billet and linkage arm have to be drilled out to a larger size to account for wear?
Again, does that rivet press out with a special tool, or can it be tapped or driven out?

I was’nt paying attention when I posted this thread... should have put it under the Crosman forum.

May be best to get a new pump arm or a billet steroid arm from Mac1?

Ron,

You must have read my mind lol. I’ve been considering a steroid job on this one all along since I bought it.
Since I think it needs a reseal along with the linkage, it might be a good time to just send it to Mac1 for the whole treatment.

In fact I put a call in to him today, but have’nt heard back yet on the overall price. This one has proven to be a nail driver, so I think’s worth doing.
Either that, or get the billet and linkage from him and do that much myself just for the experience as you suggested.