Chrysler Concorde 1993, Service Manual, Page: 211 / 820

lent is necessary for best engine cooling without cor-
rosion. Refer to Selection and Additives in this
section for appropriate coolant mixture to use.
(1) Close radiator drain. Hand tighten only.
(2) Install the cylinder block drain plugs.
WARNING: WHEN INSTALLING DRAIN HOSE TO
AIR BLEED VALVE ON THERMOSTAT HOUSING,
ROUTE HOSE AWAY FROM ACCESSORY DRIVE
BELT, ACCESSORY DRIVE PULLEYS, AND ELEC-
TRIC COOLING FAN MOTORS.
(3) Attach one end of a 6.35 mm (.250 in.) ID clear
hose that is approximately 1219 mm (48 in.) long, to
the bleed valve in the thermostat (Fig. 3). Route the
hose away from the accessory drive belt, drive pul-
leys and electric cooling fan. Place the other end of
hose into a clean container. The hose will prevent
coolant from contacting the accessory drive belt when
bleeding the system during the refilling operation.
(4) Open bleed valve.
(5) Slowly fill coolant pressure bottle (Fig. 2) until
a steady stream of coolant flows from hose attached
to the bleed valve.
(6) Gently squeeze upper radiator hose until all air
is removed from system.
(7) Close bleed valve and continue filling to the top
of the coolant deaeration pressure bottle (Fig. 3).
(8) Install cap on coolant pressure bottle.
(9) Remove hose from bleed valve.
TESTING SYSTEM FOR LEAKS
With engine not running, wipe the deaeration filler
neck sealing seat clean.
Attach a radiator pressure tester to the coolant de-
aeration bottle, as shown in (Fig. 4) and apply 104
kPa (15 psi) pressure. If the pressure drops more
than 2 psi in 2 minutes inspect all points for external
leaks.
All hoses, radiator and heater, should be moved
while at 15 psi since some leaks occur while driving
due to engine rock, etc.
If there are no external leaks after the gauge dial
shows a drop in pressure, detach the tester. Start en-
gine and run the engine to normal operating temper-
ature in order to open the thermostat and allow the
coolant to expand. Re-attach the tester. If the needle
on the dial fluctuates it indicates a combustion leak,
usually a head gasket leak.
WARNING: WITH TOOL IN PLACE PRESSURE
BUILDS UP FAST. ANY EXCESSIVE AMOUNT OF
PRESSURE BUILT UP BY CONTINUOUS ENGINE
OPERATION MUST BE RELEASED TO A SAFE
PRESSURE POINT. NEVER PERMIT PRESSURE TO
EXCEED 138 KPA (20 PSI).
If the needle on the dial does not fluctuate, race
the engine a few times. If an abnormal amount of
coolant or steam is emitted from the tail pipe, it may
indicate a faulty head gasket, cracked engine block
or cylinder head.
There may be internal leaks which can be deter-
mined by removing the oil dip-stick. If water glob-
ules appear intermixed with the oil it will indicate a
internal leak in the engine. If there is an internal
leak, the engine must be disassembled for repair.
COOLANT DEAERATION PRESSURE BOTTLE
This system works in conjunction with the coolant
deaeration pressure bottle pressure cap to keep the
coolant free of trapped air. It provides a volume for
expansion and contraction. Provides a convenient
and safe method for checking coolant level and ad-
Fig. 3 Bleeding Cooling System While Filling With
Coolant
Fig. 4 Pressure Testing Cooling System
COOLING SYSTEM 7 - 13