Stuck Impellers

Following up after 2 years (and 300 hrs!) of service on the nitrile impellers and the allen screw modification shown in this post.

I normally have been changing my impellers every 200 hrs with neoprene impellers. I changed to nitrile impellers, but they've been looking normal at that interval and I've seen no change in water flow, so I decided to extend the interval to 300 hrs to see how they do. Here's a look at the used impeller on the left and the new impeller on the right for comparison.



There was no discernible difference in the used impeller aside from the blades which were compressed against the pump cam. I'm sold on the nitrile impellers and will probably shift to a 300 hr interval when using the nitrile impeller.

Also, the allen screw mod on my pumps made the task of removing and reinstalling the back plate a true piece of cake. The allen wrench is much easier to operate in the tight confines and the knurled head screws make finger tightening/loosening very simple. I had the job completed in about an hour including removing carpet, hatches and setting up tools.



Since the impeller change went so well, I had a little extra time for a job that was staring me in the face. The tell tale signs of salt buildup indicated the HX end cap had started a little seepage.

When I removed the end cap I found why...the PO had reassembled with silicone and had not used the rubber gasket on the end cap. A trip to to the auto parts store for gasket material and Permatex and I'm back in business. Just need to do the final tightening and testing when I return to the boat next time. (Those lower hose clamps have been changed, too!)

I found the $45 for a Jabsco impeller remover somewhat steep so I bought a faucet seat remover from Home Depot and reworked it some. A whole lot cheaper than the Jabsco product, and it still does the job.

Use a toothbrush or whatever and spread Dawn between the vanes. Roll engine half a turn to spread it around. Don't start, or you will have a mess!! Once lubed, impeller usually pulls out easily with channel locks.

As is apparently the case on many boats, I have insufficient room aft of my pump for an impeller puller like ancora shows. About a year ago, I bought some pliers like this one. The jaw span is wide enough to grasp the impeller on each side of the center core between the blades.



I used them for the first time the other day and they worked great for under $10 at Harbor Freight.

FlyWright - thanks for the long term follow-up post!

Some waterproof grease on the shaft will help for next time

bayview said:

Some waterproof grease on the shaft will help for next time

Click to expand...

Would the stuff they use for swimming pools work?

Harbor Freight has those right angle needle nose pliers cheap.

On my Yanmars there is very little clearance behind the pump, I got a speed seal for the difficult to access port side, but it didn't help much, and I had trouble seating it correctly with the pump in place resulting in a leak.

The second time I changed the impellers I just pulled the whole pump. It was MUCH easier than fighting with the impeller, even on the stb side with good access. Also nice that now I don't lose any screws with the pump on the bench. I'll do it that way from now on.

Another reason for not prying with pliers or screwdrivers. is you MAY ding the edges or the sealing face of the cover plate resulting in a leak/weep when the plate does not pull flat. Those gaskets are too thin to take up much of a ding.

With those bent nose pliers a piece of scrap wood or plastic, thin, would prevent the dings.

Just something to watch out for.

C lectric said:

Another reason for not prying with pliers or screwdrivers. is you MAY ding the edges or the sealing face of the cover plate resulting in a leak/weep when the plate does not pull flat. Those gaskets are too thin to take up much of a ding.

With those bent nose pliers a piece of scrap wood or plastic, thin, would prevent the dings.

Just something to watch out for.

Click to expand...

Good suggestion, I had an old wooden yardstick that I cut into 4" pieces. I keep a couple with my spare impellers and special pliers. The impellers pop right out and the housing remains pristine.

I use these pliers from Bayshore Marine Engines.

Used the Bump Method

I had my first experience with a really "stuck" impeller on my Yanmar 440. It just beat me up, and I almost resolved to removing the entire water pump to work on it on a bench. I do use the impeller pulling tool from Bayshore Marine (pictured from LarryM). I've had this tool for years and if you do not have the the room for the Jasco, it works like a charm.

I went through some suggestions on this thread and tried a combination of ideas. After about an hour of no movement at all, I sprayed WD-40 into the shaft area and let it sit for the night. The next morning I sprayed some more WD-40 and tried again to remove it, with no success. So I then went to the suggestion of something I've never heard of - "Bump the engine". On first try, there was no movement, but after a few rounds of "bumping" and prying with the Bayshore Marine tool (using a board for a fulcrum), I could see some movement (like a 1/4"). Finally, it gave way and slid out.

Thanks for all of the suggestions!