Mercury Marine MCM 4.3L / MCM 4.3L EFI — Checking Closed Cooling System Coolant Level
Maintenance · Heat Exchanger / Coolant Reservoir
For the Mercury Marine MCM 4.3L / MCM 4.3L EFI, from the Mercury Marine service manual.
Before you start
- Allow engine to cool before removing pressure cap; turn 1/4 turn to release pressure slowly
Procedure
- Coolant level in heat exchanger should be full (to bottom of filler neck).
- When reinstalling pressure cap, tighten until it contacts on filler neck.
- Coolant level should be between ADD and FULL marks on coolant recovery reservoir.
Source: Mercury Marine service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.