Sherwood K90 Raw Water Pump

[obertra9]

I would be interested in other's experience on this topic.

I have a 1990 27 SC with the original 6 cylinder 157hp diesel engine. The marine engine include the Sherwood pump.

Pump would not self prime and pump this spring after about a 5 minute cruise when the pump inlet valve was mistakenly not opened. Eventually I rebuilt the pump (major work getting it off and on) and it now works as expected.

Before pulling the pump out, My son in law felt pretty sure that the pump just needed to be primed, we did that by pouring a gallon of water into the pump inlet hose (which never did fill up do to the impeller vanes being off). When started, it did pump water at what I guess was about 1/3 the flow volume. This was enough water for 2 one hour normal cruise at 6 knots. After pulling the pump and inspecting the impeller all 12 impeller blades were off so I was amazed that it would pump after being primed. It kept the prime between the 2 cruises.

So if you think you have a damaged pump, you can remove the heat exchanger raw water round inspection end and see how many impeller blades are broken off. Once manually primed, the pump may work endlessly (manually prime each time the raw water system is opened.) All 12 vanes were in the heat exchanger inlet cover where there is a cavity for the 3 pass raw water flow.

The Sherwood K90 pump is no longer being made as a complete pump, but the rebuild kits are readily available.

[awest]

wow. im a new member and this is like dejavu I too have the same boat, same motor and same problem Just ordered a major rebuild kit from pump vendor.com