Trouble rebuilding thomsen pump...

[monkeybrewer]

Hello All
I've recently tried to rebuild my thomsen #4 pump head and can't seem to get it to not leak. At first it holds but after a CIP or two and then when I get to product movement the leaking begins (of course!). As far as I understand I'm replacing the orings and gaskets properly, with the proper material. The metal in the pump doesn't look worn anywhere to make me think there is something wrong there. Has anyone had the same sort of problem when rebuilding these seemingly simple pump heads? Any help would be much appreciated...
Cheers

[Laughing Dog]

Jay
is it an internal or external seal pump the number 4 comes in both

Fred
Laughing Dog

[monkeybrewer]

an internal seal kit. I basically just replaced each oring, gasket and snap ring with an exact match. It seemed right, except for the fact it quickly leaks. Any thoughts?
Thanks

[Laughing Dog]

Jay
mine are external check that your shaft that holds the impeller is set correctly if it is not you dont have the pressure against the seal and they leak

Fred

[monkeybrewer]

Now that sounds like whats going on...I'll check it out tomorrow AM and let you know. Thanks for the advice
Cheers

[lhall]

Also, check the condition of the back plate where the ceramic seal presses against. They get scored up and will leak, plus eat up your seal in no time. There is plenty of steel on this plate, and you can take it down to a machine shop and have them machine it flat again for a few bucks or cases of lowfills. The seals will last much longer if you do this.

[gitchegumee]

And not just elastomers, but also the pump seal proper should be replaced. Maybe as often as once a year. Use a very thin film of food grease like Petro-gel on the o-rings to effect a very tight seal, and prevent dry bunching of the o-rings.