Replacing a Water Pump

A water pump uses a spinning iron impeller with vanes to push water at pressures far higher than atmospheric.impeller water pump This is typically done by an electric motor that turns the impeller, but there are also pumps powered by gasoline engines for use when electricity is not available or when running a large boat.

The centrifugal water pump is the most common type of marine engine water pump.impeller water pump The water comes in through the front of the pump casing and the impeller spins like a jet turbine to propel it out at great velocity, pushing the water beyond the circumference of the casing, creating tremendous pressure. This force is what is used to flush out the cooling system, and to move the boat through waves or a head of water.

If the impeller is damaged or worn out, it will not be able to exert the necessary pressure to prevent coolant from back-washing into the intake manifold and overheating the engine.impeller water pump This is usually the time to replace the impeller.

When replacing the impeller, be sure to get one with the same number of vanes as the original.impeller water pump It is also important that the style of shaft matches (keyed, splined, etc.). It is best to only refer to resources published by the engine or water pump manufacturer and to verify that the replacement fits correctly.

Before inserting the new impeller, it is a good idea to lubricate it with glycerin or some other type of water pump lubricant. This will help it slip into the housing and allow it to suck in the cooling water initially without abrading against the sides of the pump. It will also lubricate it for the 10 seconds or so until the cooling water starts flowing through the pump, giving the impeller a chance to suck in the proper amount of cooling fluid to avoid overworking the motor.

The glycerin will wash off after a while, but it will provide much needed lubrication for the short time until the pump is up to operating temperature. The same lubrication can be applied to the new gasket and o-rings. It is a good idea to only reuse o-rings that are in excellent condition.

Closed impellers have front and rear shrouds surrounding the vanes that make them less susceptible to vane failure than open or semi-open impellers. They are also easier to clean. They are commonly used in centrifugal water pumps and other types of liquids that do not contain suspended solids.

Open impellers have no shrouds in the front or rear of the vanes and are more prone to damage from suspended solids in the media. They are best suited for transporting clear water or other liquids that do not contain solid particles. Semi-open impellers are also used in some centrifugal water pumps, but they are not as efficient as closed impellers. They are less expensive and easier to manufacture than the closed impeller.

Tags:impeller water pump repair kit with housing

Impeller water pump repair kit with housing

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