4-19. WINTERIZATION SYSTEM - Continued
Refill radiator. Ensure winterization valves are open on main engine.
Start APU only (not winterization heater) and leave running for at least 15 minutes. Top up radiator as
required during this time. Check system for leaks. Tighten/remake connections as required.
While APU is running, loosen connection on winterization heater outlet and bleed air from top of heater .
Retighten hose clamp.
Stop APU and start main engine. Run engine until normal operating temperature is reached.
Check system for leaks. Tighten/remake connections as required.
Shut down engine and allow radiator to cool for 1 hour.
Check level of radiator. Top up as required.