Cleaning And Inspection - Mercury 4.2 Diesel Operation & Maintenance Manual

4. Remove the anode assembly (anode plug and the sacrificial anode) from the top of the aftercooler end cover.
b
5. Remove the anode assembly (anode plug and the sacrificial anode) from the aft end of the fluid cooler.
a

Cleaning and Inspection

Inspection and replacement interval will vary according to the condition of the seawater and the mode of engine operation.
NOTE: Using sandpaper, fiber brush, or cleaning pad, remove the deposits from the surface of the anode before trying to
determine the amount of erosion. Do not use a mild steel brush, which might leave deposits that could accelerate corrosion.
1. Remove the deposits.
2. Inspect and measure the anode. Compare the measurements to the specifications for a new sacrificial anode and replace
the anode assembly when deteriorated 50%.
NOTE: Sacrificial anodes are available only as an assembly. Replace both the plug and anode as a unit.
a
90-8M0113988 DECEMBER 2015
eng
a
b
e
b
d
c
a - Aftercooler end cover
b - Anode assembly
23266
Anode assembly
a - Anode plug
b - Sacrificial anode
c - Length
d - Diameter
e - Sealing washer
19226
Section 4 - Maintenance
Typical engine
a - Anode assembly
b - Fluid cooler
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