Filling - Mercury 4.2 Diesel Operation & Maintenance Manual

Section 4 - Maintenance
3. The coolant level in the coolant expansion tank should be above the coolant level indicator attached to the bottom of the
coolant cap.
b
a
4. If the coolant level is low:
a. Inspect the coolant recovery system for leaks.
b. Inspect the gasket in the pressure cap for damage and replace if necessary.
c. The pressure cap maintains pressure on the cooling system and may not be holding pressure properly. To have the
cap tested, contact your Mercury Diesel authorized repair facility.
d. Add the specified coolant as necessary. Refer to Add Coolant.
IMPORTANT: Tighten the pressure cap to prevent coolant loss.
5. If the coolant level is correct, install the pressure cap and tighten.

Filling

1. Allow the engine to cool.
2. Remove the pressure cap from the coolant expansion tank.
3. If the coolant is low in the coolant expansion tank, add the specified coolant as necessary to bring the level to within 25 mm
(1 in.) of the bottom of the fill neck or between the upper and lower marks, if applicable.
Description
Mercury Extended Life Antifreeze
IMPORTANT: When installing the pressure cap, be sure to tighten it securely to prevent coolant loss.
4. Install the pressure cap. Tighten securely.
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c
37255
a - Pressure cap
b - Bottom of fill neck
a
b
23248
Where Used
Closed‑cooling system
a - Filler neck
b - Coolant cap
c - Level indicator
Part Number
92‑877770K1
90-8M0113988 DECEMBER 2015
eng