Fixing Keg Pump

[Gater]

Hey guys,

A Micro Matic pump was recently left at my house. It was brought by a friend but failed about 1/4 of the way.

First, the ball at the top of the piston kept coming off, but the threads on the rod aren't stripped, so I guess I just need a new ball (Part 1 on the diagram).

Secondly, the piston rod kept getting jammed in the pump housing. You can see from the picture below that some abrasion has stripped the chrome from the rod in certain areas. I have the feeling this has a lot to do with why it was getting jammed and not pumping.

How do I take apart the pump housing so that I can try to correct the cause of this abrasion? Also, could I be missing a part or does it need to be lubricated?

Third, if I'm going to try to fix this thing, I might as well take care of the maintenance issues. As you can see from the picture of the check valve, it is grimy as are the threads around it. Should I replace it or clean it? Part number 5 on the diagram, whatever washer that is, was also real messed up, I've already peeled some of the rubber off so I guess I'll just pick another one up off the site.

So basically, any ideas of what could be wrong? How should I fix it? And is there any way to make the thing pump faster?

Thanks in advance,

Zach

[cubby_swans]

Gross. Maybe all that 'grime' was causing it to sieze up. Probably looks just as bad or worse inside the thing.

How about a nice cold glass of mold and gunk! If you're going to try and clean it, you should get some beer cleaner (look in the store here) and let it soak in that for a WHILE. The beer cleaner is designed to break up 'beer stone' or residue that beer leaves behind.

[BrewGuru]

That pump isn't that beat, I've seen MUCH worse still in service, it should clean up well.

Always remember, these things are used to KILL beer, they pump AIR into a keg, the grease and muck you see on the pump is nothing compared to that which you don't see (bacteria and microorganisms in the air) that get into the keg after the first pump and start to destroy the beer.

The abrasion on the rod is normal, from sliding along the top cap, nothing you can do about it, until the thing rusts out so bad it snaps, it will keep actuating the pump.

Replace seals 4 and 5, and if brittle, valve number 6. If not, soak in warm water and oxygen sanitizer (one step, oxy clean, etc...)and re-install. Also order new o-rings for the PROBE of the COUPLER portion of the pump - they are likely in need of replacement as well. Take the handle off of the coupler by unscrewing the small nut and you will be able to withdraw the probe.

Use pump and probe lube on all o-rings and the OUTside of the valve to ensure it seats well.

[bonefish]

...of a keg party many years ago. Some moron sprayed WD-40 on the pump. We all got lubricated, and I burped fumes for a week.
A small lesson for you.
SEAN