Chrysler RAM TRUCK 2500 1994 Service Manual page 257

7 - 2 COOLING SYSTEM •
Fig. 2 Typical Cooling System
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump on all engines to circulate coolant throughout
the system.
An optional factory installed maximum duty cool­
ing package is available for some engines on most
models. This package will provide additional cooling
capacity for vehicles used under extreme conditions
such as trailer towing i n high ambient temperatures.
COOLING SYSTEM COMPONENTS—ALL EXCEPT
DIESEL ENGINE
The cooling system consists of:
• A cross-flow radiator
• Thermal viscous fan drive
• Fan shroud
• Radiator pressure cap
• Thermostat
• Coolant reserve/overflow system
• Transmission oil cooler (automatic transmission)
• Coolant
• Water pump (to circulate coolant)
• Hoses and hose clamps
Typical coolant flow circuits for gas powered en­
gines are shown i n figure 1.
Flow—Diesel Powered Engine
COOLING SYSTEM COMPONENTS—DIESEL
ENGINE
Coolant flow circuits for the 5.9L diesel engine are
shown i n figure 2.
The diesel cooling system consists of: a cross-flow
radiator, engine driven cooling fan, thermal viscous
fan drive, fan shroud, radiator pressure cap, thermo­
stat, a vertically mounted one-way check valve (jiggle
pin) at cylinder head, a bypass hose at thermostat,
coolant reserve/overflow system, transmission oil
cooler (if equipped with an automatic transmission),
coolant, water pump, hoses and hose clamps.
Coolant is drawn from radiator into the water
pump. Water pump output is directed to the engine
oil cooler cavity of the cylinder block (Fig. 3).
From the oil cooler cavity, the coolant circulates
around each cylinder. I t then crosses to the lift pump
side of engine where i t flows up into cylinder head
through openings i n top of cylinder block (Fig. 3).
Coolant flows past the valve bridges (Fig. 4), to ex­
haust manifold side of engine and to thermostat. As
coolant flows toward the thermostat, i t provides cool­
ing for the injector nozzle.
Also refer to Thermostat Operation—5.9L Diesel
Engine. This can be found i n the Thermostat section
of this group.