Cooling System (Marine) - Detroit Diesel 92 Series Service Manual

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SERIES 92 SERVICE MANUAL
13.51 COOLING SYSTEM (MARINE)
When a Detroit Diesel marine engine is put into service at the beginning of boating season, the
following preventive maintenance checks should be made to ensure optimum cooling system
performance:
1. If the raw water pump cover was previously removed or loosened to drain the system for
winter lay-up, remove the cover, and replace the gasket with a new one before operating
the engine.
NOTE:
Failure to use a new gasket when replacing the raw water pump cover may result in
pump leakage at engine start-up. This is a change from the previous recommendation,
which allowed reuse of an undamaged gasket.
2. While the cover is off, check the condition of the raw water pump impeller. Replace
if brittle, damaged, or excessively worn.
NOTICE:
Do not over tighten standard hose clamps or attempt to
re-torque constant-torque hose clamps. Hose clamps
will break if over tightened .
3. Check the heat exchanger/raw water pump piping and hose connections for tightness and
serviceability. Replace hoses that show signs of mechanical damage ( cuts, crushing)
or deterioration ( cracks, bulged areas) or hoses that feel unusually soft or hard when
squeezed. Replace all damaged clamps.
4. If resilient isolators are used to mount the heat exchanger, replace if cracked or brittle.
5. Ensure the inhibited coolant level in the heat exchanger tank is at or near the bottom of the
filler neck and the fill/pressure cap is secure before starting. For coolant recommendations
Refer to section 5.3.1.
6. To avoid impeller damage and ensure a full flow of raw water through the heat exchanger
at engine start-up, remove the pipe plug or "zinc" from the raw water pump inlet, and
prime the pump before starting.
7. Check the condition of the fresh water pump drive belt (if used) and any other drive belts
on the engine .. Replace the belt if it is cracked, cut, glazed, or has missing cogs. Tighten
reusable or replacement belt to specifications .
M inbmation
subject.
to
change without
nctice.
6SE379 9909 Copyright© 1999 DETROIT DIESEL CORPORATION
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