CLOSED COOLED (FRESH WATER) MODELS
SERVICE MANUAL NUMBER 23
IMPORTANT: ALCOHOL OR METHANOL BASE ANTIFREEZE OR PLAIN WATER ARE
NOT RECOMMENDED FOR USE IN COOLING SYSTEM AT ANY TIME. In areas where
ethylene glycol is not available, and the possibility of freezing does not exist, it is
permissible to use a solution of rust inhibitor and pure, soft water (mixed to
manufacturer’s recommendations).
Occasionally, ensure that coolant recovery system is functioning properly by removing
pressure cap from heat exchanger and checking level. Coolant level should be up to bottom
of heat exchanger filler neck. If low, examine entire fresh water section (especially coolant
recovery system) for leaks and repair, if necessary.
IMPORTANT: When reinstalling pressure cap, be sure to tighten it until it contacts
stops on filler neck.
Pressure Cap Maintenance
Pressure cap is designed to maintain pressure in fresh water section of closed cooling
system once the engine has attained normal operating temperature. This raises the boiling
point of the coolant, thereby increasing the efficiency of the cooling system. To help ensure
proper operation, cap should be cleaned, inspected and pressure tested periodically as
follows:
WARNING
Allow engine to cool before removing pressure cap (in next step), as sudden loss
of pressure could cause hot coolant to boil and discharge violently. After engine
has cooled, turn cap 1/4 turn to allow any pressure to escape slowly, then push
down and turn cap all the way off.
1.
2.
3.
Remove pressure cap from heat exchanger.
Wash cap with clean water to remove any deposits or debris from sealing surfaces.
Inspect rubber seal on cap for cuts, cracks or other signs of deterioration. If seal is dam-
aged, cap MUST BE replaced.
4.
5.
Inspect coolant recovery gasket for deterioration and replace if bad.
Check condition of locking tabs on cap. Replace cap if tabs are bent or cracked.
a
c
b
72714
a - Rubber Seal (Cap MUST BE Replaced If Damaged)
b - Gasket (Look For Cracks Under Gasket)
c - Locking Tabs (1 Hidden)
6.
7.
Refer to “Testing Pressure Cap” and test as outlined.
Clean sealing surfaces on heat exchanger filler neck with a cloth. Inspect surfaces for
any damage or deposits that may prevent cap from sealing properly.
Page 6B-4
90-861326--1 MARCH 1999
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
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Marine readers have rated Mercury MerCruiser GM V8 GM V8 454 CID 7.4L and 502 cid 8.2L Marine Engines Service Manual Number 23 5.0 out of 5.0 based on 1 product reviews. Just need the manual. Wrote review. Can't technically review what I haven't seen yet...