Lost Impeller vanes

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I have had similar experience as AKDoug, winterizing your Jabsco head with pink plumbers antifreeze is a guarantee you will be replacing the seals, choker & flapper in the spring. Took two or three years putting kits in every spring before I finally clued in. Raised holy hell with Jabsco who pretty much suggested I should move to a warmer climate. Interestingly their repair kits now come with a warning not to use alcohol based antifreeze.
 
It's about a 2.5 hour job to do both motors on my boat. Only way to get the imoeelers out is to pull the pump. Access to port side is difficult. One of the four nuts holding the pumps on is a bear to reach.

It's not a job I want to do more than is required for good maintainence.
 
Likewise. I used to change the impeller every year, or turn it around and run it the other direction if it still felt supple. With my little Yanmar I literally have to crawl into the bilge and under the deck to reach the port side to get to the pump cover. No way to do it from above, as the access hatch is set slightly to stbd since everything else that you usually and regularly access is on the right side of the engine.
 
Best thing to do is initiate some kind of condition based maintenance. The problem is that you want to catch the potential failure before it is a failure. A few of the failure modes could be ( just brainstorming here): normal wear, dry running, hard object through vanes, abrasive sand in water, chemical attack, set vanes, hardened vanes, or increased wear due to higher discharge head.

Ideally, you'd pick an initial periodicity to change the first time. Observe the wear, and adjust the period for the next replacement. You could reinstall the impeller you just removed, but it can often be a chore to replace, so once your in there, you might as well replace.

For example, I changed mine after 12 months. It looked great. Changed the next one at 14 months. It too was fine. I kept adding two months each time. I am now at 22 month intervals. I am noticing that the fins are taking a set though. It will probably settle out at 24 months. I would probably decrease the periodicity, if I found sediment in my strainer, if I started and ran without my suction thruhull open, or if my running time hours increase significantly.

Did I save a lot of money or time? Nope. But I did decrease the potential for infant mortality, and I got to learn a little about my boat systems. I changed out screws to Allen head cap screws too. Makes it easy.

For those of you who change annually, good on ya! Periodic maintainance works too.
 
I went with allen head knurled SS screws on my RW pump. The screws start easily by hand, then using the allen wrench makes tightening in cramped quarters a cinch. Cheaper than the SpeedSeal kit...just pennies per screw at Ace Hardware.

After the pump rebuild, I went from this

img_395312_0_a0aff4db06e184f2f8bf8b37b20dcf39.jpg


to this

img_395312_1_ee0b9930179842eee2d16567f5783d77.jpg
 
When I bought my boat in 1994, the PO left a bag of used impellers. I examined them critically, bending the vanes as much as possible by hand and looking for defects. None found. I checked the pumps annually, but never found that the impellers were causing any problems. When I took the HX apart, I did find some rubber bits, so some time ago there had been impeller failures. After 6 years I sold those engines, never having to replace an impeller. On my present engines I put in new impellers before I installed them in 2000. Since then, due to bearing and seal failures, I have replaced both pumps neither had any issues with their impellers. The new pumps each came with a brand new impeller, so I now have young impellers again, in 21 years never having had one fail.

IMHO annual replacement is over-maintaining. Good on you if you do it, but it probably isn't required unless you boat in harsh conditions.
 
Maybe why my impellers last about 10 years. I don't do high mileage and we never have to winterise.
 
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