911 sc oil pump rebuild / who is doing it

[jimtweet]

Thinking it’s a good idea while it’s out to have it gone through just wondering where to send

[ajwans]

Henry Schmidt will do it for you.

That said, they are simple devices and with a few hand tools you can open, check, clean, and reassemble for yourself.

When you take it apart don't let the gears drop out before you find the end markings or mark it yourself so that you can put the gears back in exactly as they came out. Look on the intermediate shaft end of the gears for some little center dots.

There was a great thread on here regarding steps to rehabilitate a pump. Unless your engine suffered a breakage there is likely nothing wrong with your pump.

andy

[ajwans]

Here's a link to the thread where Scott Kinder describes rebuilding an oil pump: Internal Oil Pump

andy

[KTL]

Henry does it and so does Aaron at Burnham Performance and so does Glenn Yee Motorsports. I recall Henry saying the smaller pumps benefit from it more than the big pumps, for whatever that's worth.

But I would do what Andy says and just open it up for peace of mind. They are not hard to open and inspect. Just be patient and gentle taking it apart.

I would recommend opening it if you don't have any history on the engine and if you have any feelings that the engine's history could be suspect. My limited experience with a bad engine failure is simply this. A pump can look nice from the outside (and the inside where you can see some of the gerotor teeth) and it seems fine because it spins smoothly. But you never know what you can find inside.

Here's what my 964 pump looked like after it swallowed and processed a bunch of bearing debris. No way I would have EVER run that pump in an engine after I knew what had happened. But I figured what the heck why not open it since the pump is forever to be retired anyway.




Here's one of the threads where I originally posted the pictures

Can a 964 oil pump be rebuilt?

how to check oil pump health

[Walt Fricke]

Kevin - any reason why a cored pump couldn't be flame sprayed or plated and rebored true? That works on aluminum pressure plate faces when their original facing is damaged, and to an extent is what US Chrome and others do with cylinders. That wouldn't deal with scoring on the gears, but would on the housing.

Might not be economical, though.

[KTL]

I bet you're correct that a valuable pump could be saved by plating it and honing it. In the case of a common 964 pump it's probably not economical like you said. Cost of a good used pump is probably much less than trying to repair the old hosed pump.

If nothing else, I didn't throw the housing away. I put it in my bin of shamed parts. The salvageable stuff like the bolts and shafts and keys and the scavenge venturi were removed and put in a bag on the shelf. I'm sure someone will need a venturi snout at some point later on.