RAM 2500 Truck 4WD L6-5.9L DSL Turbo VIN 6 (1999)
Coolant Reservoir: Description and Operation
The coolant reserve/overflow system works in conjunction with the radiator pressure cap. It utilizes thermal expansion and contraction of coolant to
keep coolant free of trapped air. It provides a volume for expansion and contraction of coolant. It also provides a convenient and safe method for
checking coolant level and adjusting level at atmospheric pressure.
This is done without removing the radiator pressure cap. The system also provides some reserve coolant to the radiator to cover minor leaks and
evaporation or boiling losses.
As the engine cools, a vacuum is formed in the cooling system of both the radiator and engine. Coolant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
Coolant Reserve/Overflow Tank-All Except 8.0L V-10 Engine
Coolant Reserve/Overflow Tank-8.0L V-10 Engine
On 3.9L/5.2L/5.9L gas engines and the 5.9L diesel engine, the coolant reserve/overflow tank is mounted to the side of the fan shroud. On the 8.OL
V-10 engine the tank is mounted to right inner fender.
Refer to Coolant Level Check-Service, Deaeration and Radiator Pressure Cap for coolant reserve/overflow system operation and service.
Should the reserve/overflow tank become coated with corrosion, it can be cleaned with detergent and water. Rinse tank thoroughly before refilling
cooling system.
