MTU 20 V 4000 G23, Technical Publication

Page: 142 / 178

Task Description 137
6.14.2 Engine coolant – Draining
Preconditions
• Engine is stopped and starting disabled.
WARNING
Coolant is hot and under pressure.
Risk of injury and scalding!
• Let the engine cool down.
• Wear protective clothing, gloves, and goggles / safety mask.
Preparatory steps
1. Provide an appropriate container to drain the coolant into.
2. Switch off preheating unit.
Engine coolant – Draining
1. Turn breather valve of coolant expansion tank
counterclockwise until the first stop and allow
pressure to escape.
2. Continue to turn breather valve counterclockwise
and remove.
3. Draw off segregated corrosion inhibitor oil in
expansion tank through the filler neck.
4. Open drain cocks or drain plugs and drain coolant
at the following points:
• Preheating unit;
• Thermostat housing (arrow)
• U-bend (arrow)
• HT coolant pump elbow;
• Crankcase, left and right side.
5. Close all open drain points.
6. Place breather valve on filler neck and close.
M015715/00E 06-08 © MTU