Impeller
Ah, the impeller. Bane of my existence. It was a sweaty, bloody two hour job but I got the old one out and the new one in. There are no leaks, the engine seems to be staying cool. Job done.
I’m no longer as nervous about the engine as I used to be, now that I am getting to know it so well. That short piece of black hose was the key to making this task less arduous. Removing it gave me a lot more working space. The water pump is hidden behind it.
Exercising the ball valve the past several days made a big difference but it still leaks a trickle of water and needs to be replaced the next time the boat gets hauled. (The plunger trick won’t work because there’s a sea strainer over the intake – too big for a plunger to cover.) The current valve leaked three or four gallons during the course of the remove and refit. It wasn’t a problem but was an annoyance. While I was making a salt-water mess of the otherwise clean engine room I checked the engine’s pencil zincs, and they are all looking good enough to wait on replacing them for a few more months.
Ok, so maybe the water was a little more than a trickle. This is why we have bilge pumps.
The trick to getting the old impeller out is to thread the big bolt into its hub. As the bolt goes into the impeller it pushes against the water pump shaft and forces the impeller out. That’s great, but today the woodruff key on the shaft galled the bolt as it pushed in. So although I got the job done, it destroyed both of the big bolts I bought for the job. I suppose I have another 200+ engine hours to get myself new bolts for the next impeller change.
“Why isn’t Jonathan using a socket wrench, wouldn’t that save him about 45 minutes of tedious work with the box wrench? Great question! I don’t have a 1 1/8” socket on board…yet. (Also note the chopsticks I jammed in the impeller blades to prevent them from rotating as I screwed in the big bolt. Thanks for the chopsticks Simon!)
The trick to get the new impeller into the water pump is to compress it with a zip tie and to coat it liberally with dish soap. Both of those techniques worked great. I am so relieved this job is done.
In with the new.
This is the blood I was talking about. Don’t worry, I’m fine: the Chief Medical Officer cleaned and bandaged the wound for me.
