Impeller stuck on Oberdorfer water pump shaft

[dfjtessier]

The shaft/impeller/snap_ring assembly came out of my pump easily.

The snap ring came off the shaft with a little fiddling, leaving the impeller stuck on the shaft.

Any suggestions for loosening/removing the impeller would be welcome.

[Dave O]

I remove the impeller from the shaft each season for the winter and have not experienced the problem you describe. However, if I did have that problem I would probably:

Soak the bushing at the core of the impeller overnight in something like PB Blaster. People speak highly of it and it works well for me. This may damage the impeller blades as apparently PB Blaster is very tough on rubber but at least the impeller will be off the shaft.

Failing that I imagine you could grip the blades of the impeller in a vice and use a hammer and block of wood (to protect the shaft) to drive the shaft out of the bushing.

Either way the impeller will probably require replacement.

[dfjtessier]

Impeller

Thanks for the help. Interested to hear that you can remove your impeller each autumn. And encouraged that the impeller can usually be removed rather easily, making it a realistic operation to carry out whilst underway. I was thinking of removing my impeller in the fall, though I may just take out the whole impeller/shaft/snap_ring assembly.

I should have mentioned that my impeller had a couple of cracked blades and so will b ereplaced. I cut most of the rubber away getting clear access to the snap ring with my likely inferior snap ring pliers.

I may try penetrating oil. The other chemical thought I had was something like CLR which dissolves scale, though our Great Lakes waters are likely rather soft. I suppose I could resort to filing away at the soft brass?/bronze? ring or making a jig to press it out -- I am reluctant to hammer on it too hard.

Thanks again,

David
(Alberg 30 and Atomic 4 novice)

[Don Moyer]

This is one place where it makes sense to reach for a slightly bigger hammer (and a 3/8" bolt to use as a punch).

Don

[dfjtessier]

impeller removed

Took Don's advice and, after passing the shaft through a hole in an old steel plate, knocked the shaft through the impeller with a drift pin, a larger hammer and a firmer hand.

The shaft under the impeller was a little "gummy" but cleaned up easily and is in good shape.

Thanks again.

[Dave O]

As a follow-up to my winterizing comment, each fall after haul-out I run anti-freeze through the system, remove the cover plate (catching as much anti-freeze as I can) and remove the shaft assembly c/with the impeller and take the assembly home. I keep the used impeller as a spare and in the spring I reassemble with a new impeller and I'm set for a new season.

A new impeller each year is perhaps a bit of "overkill", but I do not relish the idea of having to remove the cover plate and replace a faulty impeller while on the lake with the boat pitching about and with an anxious (including me) crew.

Given the moderate cost of a new impeller I consider it fairly cheap insurance.

Dave

[boeroboy]

Drastic stickage.

I just had the same problem on a Catalina 30 I bought from a friend this winter. When we were winterizing, he tried to get old impeller off but wouldn't budge. I finally took out the shaft and throwing every clamp I had at it. No good.

I ended up needing to cut away the rubber on one side of the impeller and cutting the brass with a dremel. I didn't cut all the way to the shaft though. Just enough to loosen up and change the impeller. Shaft is still good, but soft impeller had been torqued on sometime. If it happens next year when I take out, I will get a new shaft.

[boeroboy]

Extreme stuckage.

Are posts immediate or do they need to be approved? I can't get anything to post here.

I had the same problem in a Catalina 30 I just bought from a friend this winter. When we were winterizing, the impeller was due for a change but it wouldn't come off. This spring I took out the shaft and threw every clamp in my arsenal at it with no luck. Soft brass of impeller was torqued onto shaft somehow.

Finally cut away one side of rubber and scoured the brass with a dremel. I didn't cut all the way to the shaft - just enough to loosen the impeller and pop it off with a hammer. New impeller fit fine but if it happens again next year, I will get a new shaft.

Now I have to take it all apart and change the seals. Woohoo!

[Administrator]

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[charles@pricefarrington.c]

Quick question:

What is the exact proceedure for removing the fresh water impeller?

[Baltimore Sailor]

Here's how I do it:

Take off the four screws holding the cover plate on.

Reach in with a pair of needle-nose pliers.

Pull the whole impeller/shaft assembly out.

Take off old snap ring.

Put on new impeller.

Replace snap ring.

Re-insert impeller/shaft assembly.

Replace cover and screws.

Give grease cup a turn or so.

Easy as pie!

[charles@pricefarrington.c]

You the man. Thank you. I will be attempting this process soon.

[vabiker23518]

Question on Removing Impeller

Baltimore Sailor:
Thanks for the step by step...but the impeller housing is at the aft end of the engine with the cover facing the stern. I'm trying to determine how to get at it (on my Columbia 8.7) short of removing the plugs, draping a blanket over the engine and laying on top of it. Seems to be in a very unfriendly user location, but guess thats normal with sail boats!

[Dave O]

Don sells a water pump back plate kit that might help. It's on the web site. On my C&C 29 I have lots of room and good access to the impeller so I have never bothered installing it.

But with limited room and visibility, I imagine the biggested challenge will be removing and installing the 4 screws that hold the plate in place. The kit might help with that.