Automatic Transmission Oil Coolers; Automatic Belt Tensioner - Dodge 2000 DURANGO Service Manual

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DESCRIPTION AND OPERATION (Continued)
WATER PUMP BYPASS HOSE—5.2L/5.9L
ENGINES
DESCRIPTION
A rubber water pump bypass hose (Fig. 10) is used
between the intake manifold and water pump on all
5.2L/5.9L engines.
Fig. 10 Water Pump Bypass Hose—5.2L/5.9L
1 – WATER PUMP BYPASS HOSE
2 – FAN BLADE ASSEMBLY
3 – VISCOUS FAN DRIVE
4 – WATER PUMP AND PULLEY
OPERATION
When the thermostat is in the closed position the
bypass hose allows the water pump to circulate the
engine coolant through the cylinder block while at
the same time preventing the coolant from flowing
through the radiator, this allows the coolant to heat
up quicker thus bring the engine to operating tem-
perature faster.

AUTOMATIC TRANSMISSION OIL COOLERS

DESCRIPTION
CAUTION: On in-radiator type oil coolers, if trans-
mission oil cooler is leaking, engine coolant may
enter cooler, or transmission oil may enter engine
cooling system. Both engine cooling system and
transmission oil circuit should be drained, flushed,
and inspected.
There are two types of transmission oil coolers
used. One type of cooler is the in-radiator type or oil
to coolant type. This type oil cooler is not serviceable.
The second type used is a remote type auxiliary oil
cooler or oil to air cooler. The oil to air type cooler is
located in front of the radiator, and is serviceable.
Engines
Fig. 11 Oil Flow to Cooler—Top View (Typical)
1 – TRANSMISSION OIL COOLER
2 – AUTOMATIC TRANSMISSION
3 – RETURN LINE
4 – PRESSURE LINE
Fig. 12 Auxiliary Transmission Oil Cooler—Typical
1 – RADIATOR
2 – A/C CONDENSER (IF EQUIPPED)
3 – TRANSMISSION AUXILIARY OIL COOLER

AUTOMATIC BELT TENSIONER

DESCRIPTION
Correct drive belt tension is required to ensure
optimum performance of the belt driven engine acces-
sories. If specified tension is not maintained, belt
slippage may cause; engine overheating, lack of
power steering assist, loss of air conditioning capac-
ity, reduced generator output rate, and greatly
reduced belt life.
It is not necessary to adjust belt tension on the
4.7L, 5.2L or 5.9L engines. These engines are
equipped with an automatic belt tensioner (Fig. 13)
(Fig. 14). The tensioner maintains correct belt ten-
sion at all times. Due to use of this belt tensioner, do
COOLING SYSTEM 7 - 7