Blew an O-ring in my VC tank's pump

[FreddyC]

Like the title says, but I am unsure where to place it since none of the three options give a particularly good fit. I posted photos and hope someone who has an intact pump can remove the knob you use to add/remove air and tell me which is the correct placement of the o-ring. Top view, middle view, or bottom view.
Thanks.

 

[Bubba1]

I would say top view

 

[FreddyC]

Do you have one Bubba or are you just guessing? Like I said none of them fit particularly well and I can't find an online diagram.

 

[Bubba1]

I have been a heavy equipment mechanic and machinist for 35 years so I have plenty of experience with o-rings and seals and by the looks of that I would say its the top photo no other photo makes any sense in the middle pic the o-ring would interrupt the threads in the bottom photo the o-ring would not be sealing any thing so yes my guess would be the top photo.

_________Mike

 

[FreddyC]

I would tend to agree, but it won't hold air. Right now I have it in position #3 which works, but I have to pump it up everyday. That's why I wanted someone who actually owns one to take a look at theirs. Let's not forget, it's Italian

 

[vacuumpumpman]

I would tend to agree with the top view -

do you have a model # or anything else to help identify your unit better ?

 

[GreginND]

They should fit in the grooves as shown in the first picture. If it is not holding air, I would check to make sure your o-rings are not stretched out and sliding off when you screw it in, or that they are large enough to seat in well. Also, you could use some food grade lubricant gel on it as that might help the seal.