sherwood e35 raw water pump

Our goal is to educate you about the purpose and function of many of the marine parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

No one person can know everything there is to know about the proper functioning of every boat part. That's why we've tapped the collective wisdom of our long-time technical experts to share their knowledge and expertise.

What You Need to Know About the Sherwood Raw Water Pump for Crusader

The Sherwood raw water pump was used at Crusader from the 1970s through 1992 which they installed on the majority of engines they built. Thus, Sherwood produced a vast number of these pumps. It does require maintenance, service, and winterization.

The raw water pump is used to bring the lake water or ocean water or river water to the engine for cooling. It’s used whether it’s a raw-water-cooled engine or freshwater-cooled (FWC) engine/close-cooled engine (aka heat exchanger cooled).

The names used for marine engine cooling can be a little confusing. When discussing a raw-water-cooled engine, we're talking about water from outside the boat circulating through the engine to cool it. When discussing freshwater, close-cooling or heat-exchanger-cooled engines, we’re talking about an antifreeze mixture in the engine.

The heat generated in the coolant is circulated through a heat exchanger. The transfer of the heat in the coolant is accomplished by the water outside the boat being pumped through the heat exchanger. The two liquids are in separate chambers of the heat exchanger where the heat transfer occurs.

Maintaining & Repairing Your Sherwood E35

A raw water pump is a mechanical item. The E35 has a shaft supported by bearings which are spun by a pulley that’s belt driven from the engine. There’s a rubber impeller inside the pump body which will wear over time and can overheat or fail due to lack of water. The impeller body, wear plate, and pump cam will also wear with use. Shaft sealing is provided by a robust mechanical seal.

All the service and repair parts are available for the pump. The most common repair part is the impeller, which you can easily replace. As you need more and more parts for repair, you will get to the point where the replacement will offset the cost of repair.

If you’re a hands-on boater, you can probably buy the parts and repair it yourself for less money than replacement. Timing will be a factor on how quickly you want to get back on the water, whether you order a new pump or repair the existing pump.

If you’re in an area that requires winterizing your boat, then you need to drain the raw water left in the pump. Otherwise, it could freeze and cause damage to the pump.

If you’re in a brackish water area, or a silty sandy area, not only will the impeller wear more quickly but so will the housing, the wear plate and the cam inside the pump. Anchoring in a sandy/silty area is like sandblasting the inside of the pump.

We see a lot of quicker pump failures on the Mississippi River. A lot of boaters beach the boat on a sandbar or an island. They are getting water pickup really close to the bottom of the river, and it will pull sand up through it and flood things up and cause wear and tear.

Marine Parts Troubleshooters On Call

Once a boat part fails, it's obviously too late to repair it. When possible we've provided tips on simple ways to maintain a part to cut your cash outlay. We know you'd rather be on the water having fun than on the dock calling your marine mechanic.

That said, if you need help troubleshooting a system failure, give our technical experts a call at 866-388-0390. They'd be happy to steer you in the right direction.