Cooling system. Coolant reserve/overflow system

Cooling system

DESCRIPTION

The cooling system consists of:

• Radiator
• Cooling fan (mechanical/Electrical
• Thermal viscous fan drive
• Fan shroud
• Radiator pressure cap
• Coolant reserve/overflow system (integral to upper fan shroud)
• Transmission oil cooler (if equipped with an automatic transmission)
• Coolant
• Water pump
• Hoses and hose clamps

OPERATION

The cooling system regulates engine operating temperature.

It allows the engine to reach normal operating temperature as quickly as possible. It also maintains normal operating temperature and prevents overheating.

The cooling system also provides a means of heating the passenger compartment and cooling the automatic transmission fluid (if equipped). The cooling system is pressurized and uses a centrifugal water pump to circulate coolant throughout the system.

An optional factory installed maximum duty cooling package is available on most models. This package will provide additional cooling capacity for vehicles used under extreme conditions such as trailer towing in high ambient temperatures.

Coolant reserve/overflow system

Description

The coolant reserve/overflow tank is integral to the upper fan shroud assembly and is made of high temperature plastic.

Fig. 1 Engine cooling system flow-5.2L/5.9L engines-typical

1 - Heater

2 - BYPASS*

3 - CROSSFLOW RADIATOR

Fig. 2 Engine cooling system flow-4.7L engine-typical

1 - LH CYL. HEAD

2 - BLEED

3 - THERMOSTAT LOCATION

4 - RH CYL. HEAD

5 - RH BANK CYL. BLOCK

6 - LH BANK CYL. BLOCK

7 - COOLANT TEMP. SENSOR

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.