Four years ago I replaced by Sherwood Raw Water Pump with the better Oberdorfer M202-15 unit. Has been great, but I am seeing borderline temps (190º at 80% throttle, maybe normal maybe a bit high, right?) and am thinking about pulling the cover off and having a look at the impeller vanes. Any issues with doing that? Can I just put a bit of Vaseline on the sealing ring and replace cover or must I replace, for example? I do have a spare impeller kit on board, but hate to steal its sealing ring if I don’t have to. If I do have to replace the impeller, do I need to hold the shaft in place, not letting it pull forward as on the Sherwood (on those, if you remove it, you will then have to pull the entire pump!) Any other tips?
Raw Water Pump Inspection - Oberdorfer
- Thread starter odaydokay
- Start date
You should probably replace the 4 year old impellor, inspection only reveals an impellor that has already failed not the one about to fail. Temperature should be whatever your thermostat is, mine is 160 so it maybe lower if running slowly but never exceeds 160 running hard. Don't use vaseline, use "impellor lube" most new impellors come packaged with some, I got a little tub about 25 years ago that I'll probably pass on in my will.
It depends on the engine and the pump shaft, not the type of pump.
Here's why:
Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix
Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix
c34.org
Now I know why there is a video of a guy pulling the whole shaft out of his Oberdorfer. Might be easier than fooling with the little retaining ring while the impeller is in the housing. Losing it/dropping it would not make my day either. I see your point about changing it out now, but it does not have more than 60-70 hours on it (4 years but actually 3 full seasons). I will probably wait until end of this season which for me will be only 7-8 more weekends if we are lucky. So back to the question: Pull cover and just put it on or treat that sealing ring with the impeller lube? The manual says 165-195 for operating temp, so I am not over that for sure, but will watch obviously.
I replace the impeller every 2 years, that is 100 hours. I pull the cover, remove the impeller and the shaft, clean the shaft and replace the impeller. I remove the O ring seal, clean the track, apply generous amount of lanocoat, to impeller and some light amount to shaft, insert the O ring, apply more lanocoat to are around the O ring and reinstall the cover. No leaks.
Thanks, Joe! Am I right that by pulling the shaft there is no need to remove/replace the retaining ring as one is sliding the old impeller backward off the shaft? Would not Dawn Dishwashing Liquid do the same job, tiny bit to help the impeller onto the shaft, tiny bit on the o-ring, then liberal amount on the impeller vanes?
The impeller will not come out of the other end. You still have to remove the C clamp in front and pull out the impeller. It is easier to work on replacement by pulling out the shaft. Make a note of the orientation of the slot on the back so you can insert it the same way.
The purpose of lanocoat is to prevent waterless as it will not dissolve in water. Dawn is good idea and is used to prime the pump initially. But washes away in water.
The purpose of lanocoat is to prevent waterless as it will not dissolve in water. Dawn is good idea and is used to prime the pump initially. But washes away in water.
Good thoughts and info. Much appreciate. The multi size circlip pliers I bought will be useful after all.
Lanocote is a good idea and has many uses. Thanks for reminding folks about it.
The clamp on the impeller is unnecessary. It was put there only to hold the impeller on shafts between the time they were assembled and installed. They serve no purpose once the impeller and shaft are inside the pump. Therefore, our 30 years of C34 experience is to not bother reinstalling them at all.
You also don't have to worry about the shaft slot orientation. All you have to do is place the new shaft and impeller into the pump and turn it while gently pushing. You will find out immediately when it "hits the groove."
I've been doing this for 25 years on my Oberdorfer pumps on my M25 engine.
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