Water Pump - Mercury 150 EFI Service Manual

2. Position a clean drain pan under gear housing and remove "Fill" and "Vent" screws
from gear housing.
a -
b -
3. Inspect gear lubricant for metal particles. Presence of a small amount of fine metal
particles (resembling powder) indicates normal wear. Presence of larger particles (or
a large quantity of fine particles) indicates need for gear housing disassembly, and
component inspection.
4. Note the color of gear lubricant. White or cream color indicates presence of water in
lubricant. Check drain pan for water separation from lubricant. Presence of water in
gear lubricant indicates the need for disassembly, and inspection of oil seals, seal sur-
faces, O-rings and gear housing components.
NOTE: Gear lubricant drained from a recently run gear case will be a light chocolate
brown in color due to agitation/aeration. Oil which is stabilized will be a clear yellow brown
in color.

Water Pump

CLEANING AND INSPECTION
1. Clean all water pump parts with solvent and dry with compressed air.
2. Inspect water pump cover and base for cracks and distortion (from overheating).
3. Inspect face plate and water pump insert for grooves and/or rough surfaces.
IMPORTANT: When completing gear housing repairs, that require removal of water
pump impeller, it is recommended that the impeller be replaced. If it is necessary,
however, to re-use impeller, DO NOT install in reverse to original rotation, or prema-
ture impeller failure will occur.
4. Inspect impeller side seal surfaces and ends of impeller blades for cracks, tears and
wear. Replace impeller if any of these conditions are found.
5. Inspect impeller bonding to impeller hub.
6. Inspect impeller for glazed or melted appearance (caused by operation without suffi-
cient water supply). Replace impeller if any of these conditions exist.
IMPORTANT: It is recommended that all seals and gaskets be replaced (as a normal
repair procedure) to assure effective repair.
90-883728 JULY 2001
b b
"Fill" Screw
"Vent" Screw
RIGHT HAND NON-RATCHETING
a
51871
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