Low Coolant Level Aeration; Pressure Cap To Filler Neck Seal Pressure Relief Check; Pressure Testing Cooling System; Pressure Cap - Chrysler Stratus RHD 1997 Interactive Electronic Service Manual

OVERFLOW OUTLET CONNEC- HOUSING/ENGINE THERMOSTAT FILLER NECK NIPPLE TOR MAIN SPRING GASKET RETAINER
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DIAGNOSIS AND TESTING (Continued)
internal leak in the engine. If there is an internal
leak, the engine must be disassembled for repair.
PRESSURE CAP TO FILLER NECK SEAL
PRESSURE RELIEF CHECK
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 21). Attach the
radiator pressure tester to the filler neck nipple,
and pump air into the system. The pressure cap
upper gasket should relieve pressure at 69-124 kPa
(10-18 psi), and hold pressure at 55 kPa (8 psi) min-
imum.
WARNING: THE WARNING WORDS DO NOT OPEN
HOT ON THE PRESSURE CAP IS A SAFETY PRE-
CAUTION. WHEN HOT, THE COOLING SYSTEM
BUILDS UP PRESSURE. TO PREVENT SCALDING
OR OTHER INJURY, THE PRESSURE CAP SHOULD
NOT BE REMOVED WHILE THE SYSTEM IS HOT
AND/OR UNDER PRESSURE.
Fig. 21 Cooling System Pressure Cap toFiller Neck
There is no need to remove the pressure cap at any
time except for the following purposes:
• Check and adjust coolant freeze point
• Refill system with new coolant
• Conducting service procedures
• Checking for leaks
WARNING: IF VEHICLE
RECENTLY, WAIT 15 MINUTES BEFORE REMOVING
CAP. PLACE A SHOP TOWEL OVER THE CAP, AND
WITHOUT PUSHING DOWN, ROTATE IT COUNTER-
CLOCKWISE TO THE FIRST STOP. ALLOW FLUIDS
TO ESCAPE THROUGH THE OVERFLOW TUBE.
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS, PUSH DOWN ON THE CAP AND REMOVE
IT COMPLETELY. SQUEEZING
INLET HOSE WITH A SHOP TOWEL (TO CHECK
PRESSURE) BEFORE AND AFTER TURNING TO
THE FIRST STOP IS RECOMMENDED.
VENT VALVE STAINLESS-STEEL RUBBER SEALS SWIVEL TOP
HAS BEEN RUN
THE RADIATOR

PRESSURE CAP

PRESSURE TESTING COOLING SYSTEM

PRESSURE CAP
Dip the pressure cap in water; clean off any depos-
its on the vent valve or its seat, and apply the cap to
end of radiator pressure tester (Fig. 22). Working the
plunger, increase the pressure to 104 kPa (15 psi) on
the gauge. If the pressure cap fails to hold pressure
of at least 97 kPa (14 psi), replace the cap.
CAUTION: The radiator pressure tester is very sen-
sitive to small air leaks that will not cause cooling
system problems. A pressure cap that does not
have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to the tool. Turn the tool
upside down, and recheck the pressure cap to con-
firm that the cap is faulty.
If the pressure cap tests properly while posi-
tioned the on radiator pressure tester, but will not
hold pressure or vacuum when positioned on the
filler neck, inspect the filler neck and cap top gas-
ket for irregularities that may prevent the cap from
sealing properly.
Fig. 22 Pressure Testing Radiator Cap

LOW COOLANT LEVEL AERATION

Low coolant level in a cross flow radiator will
equalize in both tanks with engine off. With engine
at running operating temperature the high pressure
inlet tank runs full and the low pressure outlet tank
drops. If this level drops below the top of the trans-
mission oil cooler, air will be sucked into the water
pump:
• Transmission oil will become hotter.
• High reading shown on the temperature gauge.
• Air in the coolant will also cause loss of flow
through the heater.
• Exhaust gas leaks into the coolant can also
cause the same problems.
PRESSURE TESTER
COOLING SYSTEM 7 - 19