Daisy 880 - when pumping pressure does not "store"

[Geoff]

My dad showed up with a neighbors 880 that had a problem.  I really don't like working on these types of guns however told him I would do a 1  2  3 to look it over.  I had hoped all it needed was some oil on the wiper.  Sadly no luck.

What happens is when I pull the pump lever I feel the pressure build though not store and the pump handle has pressure on the up stroke.

I am curious if the piece marked is supposed to move since it seems when I pull the trigger the parts that is behind it drops down as if it were supposed to pull the marked piece away from the valve area.   The piece marked does not move and I wonder is it supposed to ?

In addition, if someone knows what the problem is please share so I can either resolve it or return the gun to the owner and tell him it is toast. 

Thanks for any insight.

[BigTinBoat]

My dad showed up with a neighbors 880 that had a problem.  I really don't like working on these types of guns however told him I would do a 1  2  3 to look it over.  I had hoped all it needed was some oil on the wiper.  Sadly no luck.

What happens is when I pull the pump lever I feel the pressure build though not store and the pump handle has pressure on the up stroke.

I am curious if the piece marked is supposed to move since it seems when I pull the trigger the parts that is behind it drops down as if it were supposed to pull the marked piece away from the valve area.   The piece marked does not move and I wonder is it supposed to ?

In addition, if someone knows what the problem is please share so I can either resolve it or return the gun to the owner and tell him it is toast. 

Thanks for any insight.

When you cock the bolt that "piece" (valve stem) moves "up". You are cocking bolt before pumping right? If not it won't build pressure.

[Geoff]

I did not know this.  I will reassemble and test it.  I would think the owner who used it for short range chippers would have known this, however maybe he had a senior moment.

I tore it down and pulled the check valve and everything.  All orings look good ... I lubed the check valve shaft just because.

I will see if that all it was.   If it was, .../sighs, though I did learn things and am less hesitant to tear one apart in the future.  I will be able to add pumpers to my teardown list with pcp and springers.  ;- )

Thanks much for the tip !  I hope that is all it was.

[BigTinBoat]

Of course with the "arm" up and off the valve stem the valve spring "should" cause the valve stem to raise and seal valve.
Did you try "pushing" the valve stem "up"? It should move freely.
If you remove that "arm" you should be able to twist the valve and remove the stem. Older ones were a screw in, newer ones are a 1/4" turn to secure it. Looks to me like the stem is "stuck" in the open position for some reason.

[Geoff]

and of course the pivot pin went "somewhere" and so far no luck locating it by crawling around the basement floor.  LOL 



and of course after I hit enter I see it stuck to a small magnet I have on my workbench .. 

no luck on getting it to hold air.   maybe 1 more teardown then hand it back and tell him to go buy a new one.   1 more try then I am done with messing with this.

thanks for the help

[BigTinBoat]

I would try tapping the end of valve stem (where the little squeeze washer is) and see if it will move into the valve body.

[Geoff]

while I don't get the same feel with this pumper as I do with my working ones while pumping, when I lift that small check valve piece in my photo, air rushes down the barrel.   it's like the arm is not lifting it enough to release the air.   

[Night_Raider_]

It's been a few months, so I can't remember exactly what all was the problem with mine, but I remember it didn't store air and had pressure on the upstroke.  I don't remember exactly what I did to fix it, so I'll probably be of limited use, but as I recall all I did was add pellgunoil to the felt seal and light amounts all around in that area.  I don't remember if that truly fixed the problem, but I remember it did help.  I think it may have eventually fixed itself after a few dozen pumps (with shots every ten or less).  Sorry I can't help any more than that since my memory certainly isn't the greatest.
After thinking about it a little harder, I think it wasn't doing that every pump, but only once every 2 or 3 pumps.  It didn't slowly disappear, either.  It just sort of went away all of a sudden.

[Methuselah]

while I don't get the same feel with this pumper as I do with my working ones while pumping, when I lift that small check valve piece in my photo, air rushes down the barrel.   it's like the arm is not lifting it enough to release the air.

Maybe broke hammer spring? Pic looks like trigger is pulled but hammer not in strike position.  I just had mine apart today...

[Bryan Heimann]

Hopefully he never lubed it with stuff like wd40.  I am pretty sure I killed a solid shooting 880 with wd40 as a child and I assumed I'd wore it out with my 20 pump sessions...  If I knew then what I know now...

[Methuselah]

Get it fixed?

Inquiring minds want to know