1995 Caravelle 1900BR needs new water circulation pump (4.3L Mercruiser)

egore1

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As the title states, I need a new pump. I was down in SouthWest Florida back in October vacationing in the gulf. Had a great time, but towards the end of the vacation, I heard (faintly) an odd sound from the engine. When I got home, I was flushing the cooling system and the sound was louder. I took her in to be winterized, the mechanic said that I need the new water pump. He could grab the pulley and easily move it. (How the belt didn't come off....) The engine never overheated, so water was still circulating.
The engine serial number is OF435477.
I've seen conflicting part numbers for the replacement and I just need to find out which pump to buy. I have replaced water pumps on cars before, so I'm thinking I can save $$$ by doing this job myself. Which part # is the correct one and is the job more complicated than I think? If you need more info, let me know.

Thanks,
Ed
 

Bondo

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As the title states, I need a new pump. I was down in SouthWest Florida back in October vacationing in the gulf. Had a great time, but towards the end of the vacation, I heard (faintly) an odd sound from the engine. When I got home, I was flushing the cooling system and the sound was louder. I took her in to be winterized, the mechanic said that I need the new water pump. He could grab the pulley and easily move it. (How the belt didn't come off....) The engine never overheated, so water was still circulating.
The engine serial number is OF435477.
I've seen conflicting part numbers for the replacement and I just need to find out which pump to buy. I have replaced water pumps on cars before, so I'm thinking I can save $$$ by doing this job myself. is the job more complicated than I think? If you need more info, let me know.

Thanks,
Ed

Ayuh,.... Welcome Aboard Ed,.... It's probably easier than a car, less "Stuff" in the way,......

On the 1 to 10 scale, it's 'bout an 0.5.....
 

thumpar

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Yep, pretty easy. The hardest part is getting the block surface cleaned up. I did the pump on a 4.3l Safari van. Takes longer to get to it than replace the actual pump.
 

egore1

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Bondo, I do hope that the low end of your scale is the easier end! I know that it will save me at least $300 doing it myself.

Thanks for the replies. I'll pass along word when I've gotten the job done. It won't be this weekend - too many items on "the list".
 

egore1

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The new water pump came in on Saturday. I was going to jump right in and change it out, but I got to thinking... (and please forgive if this is a stupid question).
I've already had the boat winterized and am now curious that if I remove the old water pump, will I undo something that winterization does? Will it open a closed system? Will it expose antifreeze and drain? Am I overthinking?
Thanks.
 

Fun Times

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Will it expose antifreeze and drain? Am I overthinking?
If the engine block was filled with antifreeze for the winter, then you're going to spill some out while changing the water pump.

As long as you don't run/start the engine using water right after installing the new pump, then you'll be safe until next time you use the boat.
 

Bondo

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The new water pump came in on Saturday. I was going to jump right in and change it out, but I got to thinking... (and please forgive if this is a stupid question).
I've already had the boat winterized and am now curious that if I remove the old water pump, will I undo something that winterization does? Will it open a closed system? Will it expose antifreeze and drain? Am I overthinking?
Thanks.

Ayuh,..... If yer motor was winterized Dry, like mine, nothin' will spill out,....

If it was winterized with antifreeze, Ya, ya might wanta drain it 1st, just open the block drain on each side, way down low on the block, near the oil pan,...

No worry 'bout puttin' it back in,.... it'll be winterized just like mine,... Dry,..... Air don't Freeze,....
 

thumpar

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If you don't have closed cooling just drain it. It should be empty anyway.
 
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