Pressure Testing Cooling System; Pressure Cap - Chrysler Stratus RHD 1999 Electronic Service Manual

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DIAGNOSIS AND TESTING (Continued)
Fig. 24 Cooling System Pressure Cap to Filler 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 HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP.
PLACE A SHOP TOWEL OVER THE CAP, AND WITH-
OUT 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.

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. 25). 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.
LOW COOLANT LEVEL AERATION
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:
THE RADIATOR
through the heater.
cause the same problems.
DEAERATION
ering under the pressure cap. On the next heat up it
will be pushed past the pressure cap into the CRS
tank by thermal expansion of the coolant. It then
escapes to the atmosphere in the CRS tank and is
replaced with solid coolant on cool down.
TEMPERATURE GAUGE INDICATION
about 1/2 gauge travel. The fan will come on and the
gauge could drop to about 1/3 gauge travel, this is
normal.
ACCESSORY DRIVE BELTS
ries depends on belt condition and proper belt ten-
sion.
Fig. 25 Pressure Testing Radiator Cap
Low coolant level in a cross flow radiator will
• Transmission oil will become hotter.
• High reading shown on the temperature gauge.
• Air in the coolant will also cause loss of flow
• Exhaust gas leaks into the coolant can also
Air can only be removed from the system by gath-
At idle the temperature gauge could rise slowly to
Satisfactory performance of the belt driven accesso-
COOLING SYSTEM 7 - 19