8" barrel keg pump rebuild

[xpoc454]

I was interesting in rebuilding my 8" barrel keg pump and was thinking of getting this kit from keg works.
https://www.kegworks.com/barrel-keg-pump-repair-kit/My question is, how do you get the tower cylinder unscrewed from the coupler to get to the gasket and duck valve between the two?
Anyone has any suggestions on a tool or technique that wont damage the cylinder or the coupler?
Thanks
jim

 

[xpoc454]

Well I got the pump apart and got the replacement parts. Most of the parts fit correctly.
Taking the keg pump apart, I got to see the inner workings of a keg hand pump.

You obviously push down on the pump handle and it pressures your keg. It pushes the air from the pump through a Thomas vent. This vent is a one way vent I believe.
Now testing out my rebuilt tower pump (off a keg), I noticed an odd thing.
Pushing down and basically though the vent is what you would expect, some slight resistance on the handle.
But when I try to pull up the handle for another pump, the resistance is quite a bit. I put back on my old Thomas vent and its the same way.
Now I do have a new o-ring on the pump piston which does have a great seal.

My question, now that I look at the inner workings of this pump. On the up stroke, if the thomas vent valve is only one way, how do these pumps release the vacuum cause on the up stroke?
Is the o ring making to good of a seal? It feels great on the pump down.

Any ideas would be appreciated.
thanks