So the 140 stopped pumping up...I could hear air rushing past the pump cup.
Punching out the pivot pin.
The pivot plug.
The pump cup (remember, it's a 101 pump head, and a replacement seal of unknown provenance). It didn't look bad but seemed floppy, not stiff.
Some 95 durometer urethane rod being faced with my extreme knife tool. I ground a bunch of tools that have around 60 degrees rake, more or less.
Drilling it out.
Boring the minor diameter.
Setting the compound to about 5.5 degrees.
Turning the OD with a similar knife edge tool.
The new cup is the middle one. Left is the one that came with the 101.
I assembled it but it seemed overly tight. I also forgot the bevelled edge on the face. So I disassembled again and mounted it on a broken pump rod. I cut the bevel and turned the OD slightly smaller.
I put it all back together and pumped it up 10 times. Air was leaking past the bolt. Shot again and the bolt shot under the cover (no pic, I was having an adrenaline rush) which was a bit dramatic.
So I refurbished the bolt cover with a hole on the other end and less clearance for the locking lug, and used the old screw from my 150 (it has a head so won't allow the bolt to sneak under the cover). Anyway, I just "won" an original bolt cover on Ebay, so when it comes I'll make a new screw and it should be close to perfect (?).
I pumped it up 10 times and got 636 fps, which is great. I think if I tighten up the bolt seal and maybe clean up the flow through bolt a bit it will gain a little more. Unless something else goes wrong...I am happy I was able to make a pump cup, which is a skill that should come in handy for other projects.
Saturday, November 1, 2008
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7 comments:
I love your blog, very interesting and very well documented (photos, explanations).
Thanks
Florent
I have a crosman 140 and i am trying to find out how to replace the pump rod cup seal. Any information would be greatly appreciated. Thanks
http://www.youtube.com/watch?v=n14wkbFCKMs
Shows the type of pressing tool you need to make.
AWESOME thank you
I know this is an old blog but I am also trying to replace the cup seal on my 140 but with no luck.That link dosent work anymore, do you no of another video?
I can't find another video, best thing is to ask on the Crosman forum.
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