Hi all,
I recently drained the cooling system of a 450, and was able to flush both the radiator and the engine with a garden hose. This is after disconnecting the top and bottom radiator hoses, then adding water in either direction at the top opening.
When I tried this with a 6.9, I couldn't flush the engine - presumably there was insufficient water pressure to get past the water pump, and/or the pump has a different design that blocks the flow when the pump isn't moving.
My...