Thursday, December 07, 2006

Lessons learned: The raw water impeller.



I decided while I was waiting for parts to repair the engine I would tackle another item on the maintenance list. It was something I had been putting off for a few years. Changing the impeller on the raw water pump and installing a Speed Seal cover. I dreaded doing this because the water pump is located in a place on my Nonsuch 30 that makes it impossible to see the face of the pump cover and remove the six screws holding it in place. That is why I want to install the Speed Seal it will make changing the impeller much, much easier. At least that is what I hope.
Because of it's inaccessible location I decided to...



remove the water pump from the engine to make it easier to replace the cover and install a new impeller. As the photos above shows the old impeller was living on borrowed time and as Neptune is my witness I will never forsake it's replacement ever again! The above photo shows there is a missing vane on the impeller pump. If you look closely you will see that two other vanes are cracked and just about to fail.
Even in this condition the pump was still pumping out water vigorously in the exhaust. Which was why I was not in a hurry to squeeze my human frame into the engine compartment. But my lesson has been learned i.e. inspect and change the raw water impeller on a regular basis!



THE ENGINE SIDE OF THE WATER PUMP


A NEW IMPELLER INSTALLED

WITH THE NEW SPEED SEAL COVER INSTALLED INSTEAD OF HAVING SIX SCREWS TO HOLD THE COVER ONLY FOUR ARE NEEDED AND THEY ARE REMOVED BY HAND MAKING IT MUCH EASIER AND FASTER TO REMOVE AND CHANGE THE IMPELLER


HERE IS THE OLD IMPELLER REMOVED FROM THE PUMP IT'S A BETTER VIEW OF THE MISSING VANE AND THE TWO CRACKED VANES






5 comments:

Al Perrins said...

Gee, still had a lot of life !
The real advantage of the speed seal is that two thumb screws need only to be loosened, then the cover can be slid off when the other two are removed. The joy of not have to realign the cover really makes it special when re-
installing.

Al Perrins

Anonymous said...

AL:
I was amazed at how well the pump was still pumping even in this condition. But, it was only a matter of time before a complete failure. By the way your advice several years ago to use a a small ratchet set to remove the pump was very helpful.

Mike

rduht said...
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