GTA

All Springer/NP/PCP Air Gun Discussion General => Vintage Air Gun Gate => Topic started by: Kasilofsteve on June 19, 2022, 09:44:25 PM

Title: Benjamin 310 pump rod
Post by: Kasilofsteve on June 19, 2022, 09:44:25 PM
Need advice. I'm reassembling a Benjamin 310 and question. The pump rod, how far should it B2 the valve what's the proper length. I accidentally moved it around when I disassemble the gun going to put it back together with a new seal kit just not sure the length and how to figure that out thank you.
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 19, 2022, 11:32:00 PM
Well I went for it reinstalled the pump rod with the new seal kit getting a farting sound when pumping trying to readjust now the pump rod
Title: Re: Benjamin 310 pump rod
Post by: bantam5s on June 20, 2022, 01:55:18 AM
Sounds like it needs some oil.

You'll want to adjust it so the pump handle has to cam over a little before it's closed all the way.
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 20, 2022, 02:43:11 AM
Okay I've been trying to adjust it a few mm now it's still farts but only hold air when I cock the bolt back it seems like I'm getting closer I've gone easy on the oil just a few drops
Title: Re: Benjamin 310 pump rod
Post by: pgritty on June 20, 2022, 10:45:23 AM
Did you replace any of the internal springs?
You will have a inlet spring, an exhaust spring and a hammer spring.
Pat
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 21, 2022, 01:44:18 AM
Sorry for the late response
 Well yes but the new seal kit outlet spring is a little bigger than original. I took it all back apart and gave it a super deep cleaning inside the main tube a lot of hidden grease down by the ports. I'm going to reassemble it tomorrow in the daytime and have another go at it
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 21, 2022, 08:23:18 PM
I'm at a loss I replace the inlet Outlet Springs twice and using the original ones now, got LED washers,I think my problem is that the pump Rod seal. air is still escaping when I try to Pump It Up
Title: Re: Benjamin 310 pump rod
Post by: bantam5s on June 21, 2022, 08:28:51 PM
I'm at a loss I replace the inlet Outlet Springs twice and using the original ones now, got LED washers,I think my problem is that the pump Rod seal. air is still escaping when I try to Pump It Up
Did you not replace the pump cup on the piston ?

Maybe try posting a picture or two of any concerns you may have.
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 21, 2022, 08:31:15 PM
Yes I did replace the pump Rod cup with the new one that came with the kit that's on there now the old one wasn't supple.
I'm cleaning the felt pads with tissue paper to get old oil off. Also adjusting the length of the rod various positions trying to troubleshoot as we speak
Title: Re: Benjamin 310 pump rod
Post by: sicumj on June 22, 2022, 09:58:17 AM
Do you have air coming out the barrel when you pump?  If you followed directions above on how to adjust handle until it just cams over your pump cup is set.  When set right the cup will be flush with the inlet valve hole.  Handle will be within one inch of closing.

 It is easy to have a leak in the valve assembly or the lead seals.  Pictures would help.  I like tapping my valves with a wooden dowel to help seat them.

Jim
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 23, 2022, 12:04:40 AM
Do you have air coming out the barrel when you pump?  If you followed directions above on how to adjust handle until it just cams over your pump cup is set.  When set right the cup will be flush with the inlet valve hole.  Handle will be within one inch of closing.

 It is easy to have a leak in the valve assembly or the lead seals.  Pictures would help.  I like tapping my valves with a wooden dowel to help seat them.

Jim
Thank you I will give that a try with the wooden dowel and try and seat the valve closer I will try and reset the bolt handle two and see what happens. Pictures don't like me here can't seem to upload even on Photobucket I'm picture challenged
Title: Re: Benjamin 310 pump rod
Post by: DanD on June 23, 2022, 12:44:53 PM
Just cock the gun before pumping. It's a non-issue. It's "farting" when uncocked because the exhaust valve spring is weaker than the hammer spring- which is a good thing because it ensures you'll dump more air at higher pump counts.
Title: Re: Benjamin 310 pump rod
Post by: Kasilofsteve on June 24, 2022, 01:28:54 AM
Good advice Dan at first you don't succeed try try again. Success😃 the larger exhaust valve spring did the trick I was able to sandwich it back into the tube and it worked first pump held air I'm in business thanks for all your help guys.
If I stare at something long enough I'll figure it out kind of weird