Mitsubishi S12A2 — Change the coolant
Maintenance · Cooling system
For the Mitsubishi S12A2, from the Mitsubishi owner's manual.
Applies to: Mitsubishi S12A2, Mitsubishi S12A2 engine
Before you start
- Check coolant level only after the engine has stopped and the filler cap is cool enough to touch.
- Dispose of drained antifreeze coolant according to local regulations.
Procedure
- Run the engine until coolant temperature reaches 70 to 80°C [158 to 176°F].
- Allow the engine to cool to room temperature, relieve pressure and remove the radiator cap.
- Loosen the engine and water pump drain plugs, remove the radiator drain plug and drain coolant.
- Remove the drain plugs of the air cooler pipes and drain.
- Flush with cleaning solution at 800 to 900 rpm for about 15 minutes, drain.
- Fill with clean water, run at 800 to 900 rpm for about 10 minutes, drain; repeat until draining water is clear.
- Pour pure undiluted LLC into the radiator, then add soft water slowly to the required concentration.
- When full, tighten the radiator cap, crank the engine several times for 10 seconds to bleed air.
- Operate until coolant is 70 to 80°C, stop and check the coolant level.
Tools required
- Container Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- LLC concentration 30% at -10°C, 40% at -20°C, 50% at -30°C, 60% at -45°C
Full service-parts list: Mitsubishi S12A2 →
Source: Mitsubishi owner's 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.