4. If the recovery bottle is empty of fluid, allow the engine to cool to the ambient air temperature.
5. Remove the cap from the heat exchanger and observe the fluid level.
Heat exchanger cap
6. The coolant level in the heat exchanger should be at the bottom of the filler neck. If the coolant level is low, contact your
authorized Mercury MerCruiser dealer.
7. Install the cap onto the heat exchanger and tighten it until it seats on the filler neck.
Filling
NOTICE
Using propylene glycol antifreeze in the closed cooling system can damage the cooling system or the engine. Fill the closed
cooling system with an ethylene glycol antifreeze solution suitable to the lowest temperature to which the engine will be
exposed.
NOTICE
Without sufficient cooling water, the engine, the water pump, and other components will overheat and suffer damage. Provide
a sufficient supply of water to the water inlets during operation.
NOTICE
Air trapped in the closed cooling system can cause the engine to overheat, resulting in engine damage. Minimize the
possibility of trapping air when initially filling the closed cooling system by positioning the boat so that the front of the engine
is higher than the rear of the engine.
NOTE: Add coolant only when the engine is at normal operating temperature.
1. Remove the fill cap from the coolant recovery bottle. Inspect the gasket and replace if necessary.
IMPORTANT: Coolant flows at a high rate of speed in this closed cooling system. Higher idle speeds can trap air in the
system and make purge procedures more difficult. Operate at idle when filling the system or purging air.
2. Fill to the full mark with the specified coolant.
Tube Ref No.
Description Where Used Part No.
122
Extended Life Antifreeze/Coolant Closed cooling system 92-877770K1
3.
Check the antifreeze concentration for adequate freeze protection and correct if necessary. Refer to the Specifications
section.
4. Install the fill cap to the coolant recovery bottle.
Changing
Contact your authorized Mercury MerCruiser dealer.
Section 4 - Maintenance
Page 50 90-8M0128973 eng MAY 2017