Sprinter 3500 V6-3.0L DSL Turbo VIN 45 (2007)
Radiator Cap: Description and Operation
Operation
OPERATION
A vent valve in the center of the cap will remain shut as long as the cooling system is pressurized. As the coolant cools, it contracts and creates a vacuum
in cooling system. This causes the vacuum valve to open and coolant in reserve/overflow tank to be drawn through connecting hose into radiator. If the
vacuum valve is stuck shut, or overflow hose is kinked, radiator hoses will collapse on cool-down.