Sherwood, Kohler Gasoline Engine Water Pump - G907P.
Manufacturer's original equipment
Fits Kohler engine model: 344089
G907P Service Bulletin
Assembly and Disassembly instructions as provided by Manufacturer
Disassembly (numbers in white)
Remove the screws and lock washers that hold the body and housing together.
The housing assembly including the impeller can be removed from the body assembly, along with the o-ring, spacer plate and gasket.
Remove the woodruff key from the shaft. If the shaft is to be used again and if it is put in a vise, always use lead over the jaws of the vise so that the shaft is not damaged.
Remove the retaining ring from the shaft (impeller end). The shoulder washer and seat assembly can now be removed.
From the drive end of the pump (pulley end, hub end, shaft end) remove retaining ring, remove pin, remove woodruff key, loosen set screw if used.
NOTE: If the pulley or hub is pressed on the shaft it will be necessary to locate a support directly between the pump body and pulley or hub as close to the shaft as possible. Press the shaft out of the pulley or hub. Make sure the body is free and not supported.
Remove the large internal retaining ring from the body at the end of the bearing.
Support the body and press the shaft, bearings, spacer and retaining ring out thru the bearing or pulley end of the body.
The seal assembly is pressed into the body. It can be removed by pushing a tool thru the bearing end and up against the metal or back side of the seal.
NOTE: On some pumps there is a spacer located between the pulley (hub) and bearing on the shaft. On other pumps the bearings are positioned on the shaft with a retaining ring on each end. Support the bearings on the inner race and push the shaft out of the bearings.
Assembly (numbers in black)
When assembling the cam, put Permatex #1 on the backside of the cam and the screw that retains the cam. Wipe off any Permatex that gets into the impeller cavity.
Assemble a retaining ring on the shaft into the second groove from the impeller end. Push the ball bearing over the shaft. Press on the inner race of the bearing. Push the bearing up against the retaining ring. (Push the bearing on from the pulley or drive end.)* Assemble a spacer and then the second ball bearing. Assemble the second retaining ring over the shaft and up against the ball bearing if required.
There is a large internal retaining ring located in the body that provides a shoulder for the bearings if it has not been removed. Approximately 1.38 inch from the bearing end of the body. If it has been removed it must be reassembled at this time.
Press the mechanical seal into the body from the impeller end. Make sure that seal is pressed in square. A tool should be used to assure proper assembly.
Push the bearing and shaft assembly into the body using care not to cock the bearing. A tool is recommended that will give you uniform pressure on the bearing outer race. Lock the bearing in place with the large internal retaining ring.
Assemble the seat assembly, shoulder washer and retaining ring over the shaft from the impeller end. Locate the white ceramic surface against the seal – Do not damage (scratch) the white ceramic surface of the seat or the seal and seat assembly might leak. Lubricate the rubber part of the seat and use a tool for ease of assembly.
Press the woodruff key into the shaft. Make sure the brass key is used at this location.
Assemble the impeller into the housing.
Assemble the gasket and spacer plate on the body, and line up the screw holes.
Make sure the o-ring is properly located in the groove in the housing. A small dab of grease will help hold it in position until the housing to body screws are tightened.
It may not be necessary to completely disassemble your pumps unless you want a complete or major repair. You should first determine, if possible, the cause of your pump problem.
Failure to prime or pump. (Generally, impeller, cam, and or cover wear.)
Leaking through drain holes in the bearing housing. (Seal problem)
Shaft wobble. (Major repair/wear of bushing, bearing, and or shaft.) It is recommended when replacing the seal or seat that you replace both at the same time. Before assembling the pump, all parts should be inspected and parts replaced if excessive wear is noted.
Sherwood Technical Tips
Sherwood recommends replacing your impeller annually. However, as usage may vary vastly, Sherwood does have some storage tips for those who do not have many hours on your engine.
Storing your impeller in a cool dark place avoids the following problems:
Copper Bonding to the impeller as it sits in the housing
Vanes "setting" in the position as stored in the housing
Ultra Violet (Sunlight) deterioration
Sherwood suggests three easy tips to help you install your new impeller
Use a non-petroleum based lubricant (i.e. silicon or soapy water) to help slide in the impeller
Install the impeller with a twisting motion onto the shaft. Never force the impeller onto the shaft. The impeller must move freely on the shaft. The impeller must move freely on the shaft to properly prime and function
Use a small amount of non-petroleum based lubricant to help hold the o-ring when replacing the cover
Sherwood recommends inspecting your impeller closely during any pump maintenance. Replace the impeller if you discover either of the following.
Tear or rip on any of the impeller blades. Flex the blades to examine more thoroughly.