Raw water pump

[S/V Laelia]

My raw water pump has been dripping for a while now and I have finally gotten a new pump. The old one has a bunch of brass fittings added to make the plumbing work when the pump is installed with the water flowing in a vertical direction - in at the top and out at the bottom.

Is there any reason why the pump couldn't be rotated 90 degrees so the water comes in from port and out to starboard? It would simplify the plumbing considerably.

Also, the hoses are 3/4" i.d. but the pump has 1/2" fittings. I will probably be replacing the hoses. Do they need to be 3/4" or can I go with 1/2"?

Anything I should know about doing the replacement? I have read the service bulletin about the alignment procedure - is there anything else to know?

Thank you,
Ralph

[SVJourney]

The pump on Journey has the fittings at 3 and 9, so it doesn't matter which way they go in or out. 

The hoses are 1/2 and the inlet/outlet are 3/4.  the inlet into the heat exchanger is 1/2, so I'm sure that is what it needs.  Definitely no problem with flow.

Be sure to do an alignment!  I found out the hard way that the Sherwood pump needs to be installed finger tight, then spin the engine a few times to align the shaft.  Otherwise it will be miss-aligned, and vibrate and give you very short seal life.

[S/V Laelia]

Thanks for the info. I couldn't see any reason why it wouldn't work but best to be sure. I wonder why the PO went to the trouble to do it the way they did?

[S/V Laelia]

I crawled back into the cockpit locker to get ready to install the new pump and discovered the reason for the old setup - the intake plumbing would interfere with the belt on the front of the engine if I just ran a straight shot across to the port side of the boat.

That lead me to make another attempt to get the old plumbing fixtures off the old pump. I was not happy to find that the old pump has larger fittings than the new one. The old pump has openings that are about 1" i.d. - the new one is 3/4".

The W40 parts manual lists 3 pumps. One is belt driven so I can eliminate it. The remaining part numbers are 11020 and 16423. I got my pump from Torrensen. Their parts catalog show that the 11020 has been replaced by 16423 - the one I ordered.

Is it OK to use this pump or is there actually another pump?


I did some more online searching to see if there is another pump. It looks to me like the old part# 11020

[S/V Laelia]

I made a leap of faith and installed what I have. Shouldn't be hard, eh - four bolts and two hoses. What could go wrong?

It "only" took about 4 hours. First of all, there was the problem of getting the notch in the pump shaft to line up with the ridge in the engine shaft. After trying several different things, I realized that the two studs sticking out of the engine were removable. Once I got them out, it was no big problem to match up the parts and rotate the pump to where the bolt holes matched up. I only dropped two lock washers into the engine compartment in the process of getting them onto the studs. I think one is stripped - it pulls up to a certain point and turns without getting any tighter. The stud looks fine when I pull it out and it threads back into the hole OK - but I don't like this. Naturally it is the one that is hardest to reach - the one on the lower left when viewing the engine from the engine front.

I got it all together - I did remember to do the alignment procedure outlined in the W40 service bulletin.

Getting the intake hose on was no problem. The outlet hose required a lot of pushing and cussin' - probably because I couldn't find a combination of parts that ended up with a hose barb. I had to settle for filing the threads off one end of a 2" nipple. I would like to have gotten it on farther but I think it is OK.

I fired up the engine for a test and quickly shut it down when I remembered that I had closed the seawater intake seacock. I opened it and tried again. All is well - there is water coming out the exhaust in the usual way.

I did a visual check on the pump to see if there were any leaks. It looks fine.

But wait - there are drips of water coming from somewhere. A brief look also turned up spurts of what looked like and smelled like exhaust. It looks like there is a crack in the part of the exhaust system shown below.



Any idea what this is called and where I can find a new one? Is there better way to do what this part does?

[S/V Laelia]

I'm going to start a new thread about the exhaust problem. I think this one is done for.

[SVJourney]

The pump we have onboard is made by Sherwood, part number G65.  Its major overhaul part number is 12221, but you can easily get new bearings and seals from any bearing retailer and get your old pump overhauled.  We just did it in Nassau Bahamas and it cost $120 for parts and labor, not including a impeller.  Should be even cheaper in the States.