Water Pump Cleaning And Inspection - Mercury 150 EFI Service Manual

Water Pump Cleaning and Inspection

1. Inspect the water tube coupling for wear or damage. If necessary replace.
a -
2. Inspect the water pump impeller for wear on the end, top and bottom of the impeller
blades. Replace the impeller if this condition is found.
3. Inspect for proper bonding between the hub and the impeller. Replace the impeller if im-
proper bonding is found.
a -
b -
4. Inspect the impeller blades to see if they are cracked, burnt, hard or deformed. Replace
the impeller if the blades are in this condition.
IMPORTANT: The circular groove formed by the impeller sealing bead should be dis-
regarded when inspecting cover and plate. The depth of the groove will not affect wa-
ter pump output.
5. Replace cover if plastic is melted from excessive heat (lack of water). Replace stainless
insert and/or face plate if grooves (other than impeller sealing bead groove) are more
than 0.010 in. (0.254 mm) deep.
a -
b -
c -
d -
IMPORTANT: It is recommended that all seals and gaskets be replaced (as a normal
repair procedure) to assure effective repair.
IMPORTANT: It is recommended that the water pump impeller be replaced whenever
the gearcase is removed for maintenance. However, if it is necessary to re-use the
impeller, DO NOT install in reverse to original rotation as premature impeller failure
will occur.
90-883728 JULY 2001
a
Water Tube Coupling
a
Hub
Impeller
b
Water Pump Face Plate
Sealing Groove (disregard)
Water Pump Cover
Stainless Insert [discard if grooves exceed 0.010 in. (0.254 mm)]
b
a
COOLING
c
d
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