raw water pump system

[ontariojeff]

Hello,

I have been reading helpful information from this site for years.
Figured it was time to join.

I have a list of questions but for now I will try to stay focused on my main issues.

Seems my raw water motor for my closed circuit heating/cooling may be seized. I have purchased a 1/3 hp replacement.
It was a nightmare removing the old one, I have taken off the four bolts holding the electric motor to the pump.
Now the damn motor will not separate from the pump system no matter how hard I try.
Thinking the drive shaft may be screwed or somehow attached to the pump?

Also the power to the motor on the electrical panel tests with no voltage? Think I may have blown a fuse, there are no breakers tripped on the inside galley panel.

Thanks.

[km1125]

Post some pics of what you're dealing with. Usually those motors come as an assembly because they're magnetically coupled to the impeller.

[ontariojeff]

Thanks for the reply.

Here is a pic of what I'm dealing with.
Note the yellow screwdriver in the small crack where it will not seperate.

20220220_100107[1].jpg

[bud37]

I have no experience with that unit you have there......just a guess here.....but looking at the pic it appears you will have to remove that assembly and see if there is a locking circlip on the shaft end in the pump chamber . It looks like those shiny bolts have been apart judging by the lack of corrosion on them.

What is the name on the assembly ?

Have a close look to see if there is a clip under that corrosion inside that area next to the screw driver.

[km1125]

Wow. That's interesting. The actual pump part looks like a Sherwood impeller pump. I wonder if that space between the pump and motor is a alignment/isolation coupling. Can you see inside there? Does the shaft go right through to the pump or is there some kind of coupling in there?

What's the shaft look like on the NEW motor?

If that's the kind that has a mechanical seal then perhaps the shaft goes all the way though to the impeller, with a nut on the end, like this:

seawater_pump.jpg

[ontariojeff]

Great advise guys, thanks.

The new pump shaft looks like this...

[bud37]

Yup ...theres your answer right there....if there is a seal in there in the pump housing which there probably is, it would be wise to replace it new while you are at it......the groove is probably to hold the shaft still while tightening....good luck man, looks easy from here....so long as when you get it apart the new matches the old...

[km1125]

If you've never dealt with the mechanical seals before (ceramics), then do some poking around about them. The key is to keep them CLEAN when you're removing and installing and make SURE you don't chip the ceramic or otherwise get dirt (even fingerprints) on the mating surfaces. Any dirt there will grind into the mating surfaces and make them not seal properly forevermore.

[Viper]

If the impeller is threaded onto the shaft, it seems to me the assembly wouldn't come apart by prying it at that location. I would think you'd have to dismantle the opposite end and remove the impeller first before you can separate the pump assembly from the motor. I would remove the entire assembly including the strainer and dismantle everything on a bench. This will also afford you the opportunity to clean up the green death on everything and and coat it. It'll also allow for inspection of the inside of the pump. If there's a seized bearing, a new motor won't do you any good. Inspect the seals too, if they're aged/cracked, you'll be dismantling again soon if you don't replace them now.

Good luck and keep us posted.

[ontariojeff]

Great advise, was able to seperate the impeller.The new motor fit fine.
Just some replacement 1/2 in hose and I will have A/C (and heat) again!

Thanks all.