Obendorfer sea water pump - 1989 Catalina 30 with M25 XP diesel

[pullark]

Hello,
I have noticed some water loss from the weep hole so time to rebuild my Obendorfer pump. I believe it is a 202M-15 of late 80s vintage. I definitely need new seals and the carbon bearing has degraded at one end (engine) with a few chips of material missing. I have a couple of questions for the wise members of this group. Do I need to replace the bearing if only a few millimeters missing? I believe the shaft is well supported and shows no sign of wear. Also has anyone tried a workaround for the Obenforfer seals? Is there any reason why a conventional oil seal (x2) wouldn't do the job? I'm not sure if a seal of the right dimensions available but if it was is there any reason why it couldn't be deployed? The OEM seals seem stupidly expensive for what they are. I'm in Aus so I haven't attempted to source some OEM seals locally but I'm thinking they will be as dear as poison. Thoughts please. Cheers Kevin

 

[kloudie1]

The carbon should be replaced since it has to exactly center the shaft so that the seal works properly. The seals usually can be found at a ball bearing supply place . It may be that the shaft should be replaced as well if the old seals have worn a groove in it. Not good news, sorry.
I rebuilt one many years ago; we used an oilite bronze bearing instead of carbon, and drilled and tapped the bearing holder for a grease cup. The cup is an old fashioned thing that contains grease ; before cranking up, you could turn it a half turn or so to grease the bearing.

 

[jonelli]

Just another option, new pumps can be had for $300-ish. I bought the rebuild kit then just bought a new pump when they were closer to $200 and change. Just checked downwindmarine and prices are $300ish now.

 

[pullark]

Thanks for your thoughts guys. I have found solutions for lack of specific Oberdorfer parts here in Aus. I sourced a graphite bushing which is three inches long and exactly right bore size 0.625 in . This item cost $AUD16.00 which is around $USD12.00. I just need to skim a little off OD with lathe to get a nice fit into pump bore. Bought two oil seals for $6.00. If I had shipped OEM parts from US I reckon it would have cost over $130 just for seals and bush. I can machine two bushes for a cost of $AUD8.00 each (vs around $USD 35 each for the genuine article). So the moral of the story is shop around and improvise with (proper engineering)fit for purpose alternatives.

 

[mikeracca]

I always liked having a lathe around when I was younger. My dad was a machinist and we had one in the garage. I would make all sorts of things on it, from an anvil paperweight, a bell, and even a cannon. Plus some bushings for RC cars and even my real car when I got to that age. Very handy tool.

 

[JoeWhite]

Puller, can you share the dimensions and source of the bushing and seals?

 

[jonelli]

Puller, can you share the dimensions and source of the bushing and seals?

All the parts for the 202M pump are at Downwind Marine for pretty reasonable prices:

Departments - Oberdorfer Model 202M Rubber Impeller Pumps - Universal Engines | San Diego Marine Exchange

Model 202M Rubber Impeller Pumps for Universal Engines Bronze Construction with Flange Mount These engine-cooling impeller pumps are designed specifically for the flange mount of Universal Series gas and marine diesel engines. Direction of shaft rotation determines inlet and outlet ports...

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