Testing Pressure Cap - Mercury MerCruiser D2.8L D-Tronic Service Manual

SERVICE MANUAL NUMBER 22

Testing Pressure Cap

Pressure cap is designed to maintain a pressure of approximately its rated capacity (refer
to Specifications) in closed cooled section once engine has attained operating temperature.
Cap should be cleaned, inspected and pressure-tested at regular tune-up intervals or
whenever cap is suspected of maintaining improper pressure.
Allow engine to cool before removing pressure cap. 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. Carefully remove pressure cap from reservoir or heat exchanger.
2. Wash cap with clean water to remove any deposits or debris from sealing surfaces.
3. Inspect gasket (if used) and rubber seal on cap for tears, cuts, cracks or other signs of
deterioration.
4. Replace gasket, if damaged, or entire cap if rubber seal is damaged.
5. Ensure that locking tabs on cap are not bent or damaged.
90-860074-1 FEBRUARY 2002
a - Rubber Seal
b - Gasket
c - Locking Tabs (1 Not Shown)
WARNING
a
c
CLOSED COOLING SYSTEM
b
Page 6B-15
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