Raw water pump failure on Westerbeke 70

[Calypso52]

I replaced the water pump">raw water pump 1400 hours ago. Pump is now dribbling water at a healthy rate and leaving a rusty stain.
At the time eight years ago a new one was about $425. A new one now is $925! Rebuild kit is $180. Some one in the distribution chain is making a healthy profit.

So here are the questions:

Does anyone have a sense of the normal lifespan of a raw water pump?

What is the consensus on new v. rebuild? I am inclined towards rebuild this time for obviously reasons. But I believe it requires a hydraulic press to get the new seal in there so I would need to find a mechanic to do it for me. Or can I do this under the shade tree?

What is a reasonable amount of labor? 1-2 hours? So now I am up to $400 total parts and labor, half the cost of a new one.

Does a rebuilt pump, done properly, last as long as a new one?

Is this just highway robbery from Westerbeke or does everyone pay this on their engines?

Thanks!

[model 10]

if the pump has both bearings replaced both seals the cam the shaft the impeller, the cover it's probably as good as new but do they do all that?

[MarkSF]

You've done very well, getting 1400 hours out of it. My last Sherwood lasted about 200 hours.

Personally, I would buy a new one, then get the old one rebuilt and keep it as a spare. That is what I have done, having had cruising plans wrecked by the leaking pump.

You do indeed need a hydraulic press.

[nigel1]

Not sure what pump you have, but rebuilding yourself should be easy enough.

Here is a link to some very useful info.

Rebuilding A Raw Water Pump Photo Gallery by Compass Marine How To at pbase.com

[Stu Jackson]

Yup, replace the seals, simple thing to do.

Oberdorfer Pump Rebuild 101 - Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix

Much like Maine Sail's writeup.

Also, try Depco Pump Company for great prices.

[Lepke]

I have a couple generator engines that have Sherwood or similar pumps. The bearings and seal are tight fits, but removable by hand. If you need a bearing press, most bigger auto parts stores will press off and on bearings if you buy the bearings there. Another option is is an arbor press (hand press), about $40-50. And another option is using a vice and a combination of large sockets or pipe to press the bearings. Inspect the shaft where the seal contacts it.
Roller bearings have numbers on their sides. You can buy them online.
Seals often go bad when sitting for long periods. Pumps with bushings instead of roller bearings don't last as long, but are still rebuildable. Several of my pumps are 1000's of hours old, but new seals added when the boat was bought.

[Stu Jackson]

Originally Posted by Lepke

I have a couple generator engines that have Sherwood or similar pumps. The bearings and seal are tight fits, but removable by hand.

You can press the seals out with a deep well socket, a piece of wood and a mallet.

Why Sherwood pumps leave a lot to be desired compared to many others:

Why SHERWOOD Raw Water Pumps leave a LOT to be desired: CNG & Sherwood Pump Dissection Thanks to Ken for that one, I'm tired of repeating it. - Stu 5/25/2015

[scallywag]

Who made the pump? Is it a bolt on? Did you try to put grease around the pulley shaft on the inside? If you go straight to a Westerbeke dealer you will pay top dollar. I paid 135 to have the starter rebuilt. Of course I pulled the starter. I pulled my water pump numerous times to replace the impeller. There are only a couple impeller makers even though the engine manufacturers have their name on the box. Just some thoughts. I hope it helps.

[Calypso52]

Thanks all the replies and links. Hopefully the pump lasts another dozen hours for our final summer cruise. It is belt driven, easy to remove. I'll take it off and see if I can take it apart using your suggestions. I'll let you know how it turns out.

[Blue Stocking]

Not familiar with your model, but W/Bekes with camshaft or gear train driven pumps are very susceptible to misalighnment. When re-installing, leave nuts fingertight and roll the engine a few times. Then tighten nuts when pumpshaft tenon has aligned on the inside. THIS IS CRITICAL WITH THE W46 MODEL.

[Scrimshaw4]

While Westerbeke uses a Sherwood pump that can be purchased new for considerably less, Westerbeke mills the foot of the pump, base angle and width, to align it in the pump bracket with the pully. They could have engineered the bracket for proper alignment but this way the force you to buy the pump from them at a rediculus mark-up. Rebuild your existing one. It's cheaper and will last just as long.

[Valmika]

My pump went out on my Westerbeke 42 and I was able to get a Vetus replacement for $135 Don't assume you have to buy one from Westerbeke

[Valmika]

Sorry mine was the fresh water pump

[wayne.b]

Originally Posted by Stu Jackson

Yup, replace the seals, simple thing to do.

Oberdorfer Pump Rebuild 101 - Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix

Much like Maine Sail's writeup.

Also, try Depco Pump Company for great prices.

===

If the seals are gone the bearings are highly suspect and should be replaced also.

[Exile]

Someone please correct me if I'm wrong, but can't raw water leakage also be caused by simple wear on the cover plate? Often they have paper gaskets which aren't very good, which is why Maine Sail recommends adding some sealant. If my understanding is correct, wear b'twn. the impeller & the inside of the cover plate can lead to a poor seal. The 'Speedseal' product largely remedies this, assuming there's one to fit your particular pump that is. I carry one or two spare cover plates & gaskets onboard.