Jeep 1996 Grand Cherokee Service Manual - page 195
COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic 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 cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
COOLING SYSTEM COMPONENTS
The cooling system consists of:
• A radiator
• Cooling fan
• Thermal viscous fan drive
• Fan shroud
• Radiator pressure cap
• Thermostat
• Coolant reserve/overflow system
• Transmission oil cooler (if equipped with an
automatic transmission)
• Coolant
• Water pump
• Hoses and hose clamps
SYSTEM COOLANT ROUTING
For cooling system routings refer to (Fig. 1) (Fig.
2).
WATER PUMP BYPASS HOSE—5.2L V-8 ENGINE
A water pump bypass hose (Fig. 3) is used between
the intake manifold and water pump on all 5.2L V-8
engines.
COOLANT
The cooling system is designed around the coolant.
Coolant flows through the engine water jackets
absorbing heat produced during engine operation.
The coolant carries heat to the radiator and heater
core. Here it is transferred to ambient air passing
through the radiator and heater core fins. The cool-
ant also removes heat from the automatic transmis-
sion fluid in vehicles equipped with an automatic
transmission.
RADIATOR
All vehicles are equipped with a cross flow type
radiator with plastic side tanks.
Plastic tanks, while stronger than brass, are sub-
ject to damage by impact, such as from tools or
wrenches. Handle radiator with care.
DESCRIPTION AND OPERATION
AUTOMATIC TRANSMISSION OIL COOLERS
There are two types of automatic transmission oil
coolers:
• An oil-to-coolant type. This is supplied as stan-
dard equipment on vehicles with an automatic trans-
mission. It is mounted in the radiator outlet tank.
• An external auxiliary oil-to-air cooler. This is
supplied as optional equipment. It is mounted in
front of the radiator and air conditioning condenser
and behind the grille.
COOLANT RESERVE/OVERFLOW SYSTEM
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
• A volume for coolant expansion and contraction.
Fig. 1 Engine Cooling System—4.0L Engine—
Typical
7 - 2
COOLING SYSTEM
ZJ
GENERAL INFORMATION (Continued)