2005 CHRYSLER CARAVAN cooling

REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL).
(3) Place the instrument panel center bezel unit
face down on a suitable work surface. Take the
proper precautions to protect the center bezel from
cosmetic damage.
(4) If the vehicle is equipped with the optional
Automatic Temperature Control (ATC) system, dis-
connect the infrared sensor jumper harness connector
from the receptacle on the back of the A/C-heater
control (Fig. 9).
(5) Remove the six screws that secure the A/C-
heater control to the back of the instrument panel
center bezel.
(6) Remove the A/C-heater control from the instru-
ment panel center bezel.
INSTALLATION
(1) Position the A/C-heater control onto the back of
instrument panel center bezel.
(2) Install the six screws that secure the A/C-
heater control to the back of the instrument panel
center bezel. Tighten the screws to 2 N´m (17 in.
lbs.).
(3) If the vehicle is equipped with the optional
ATC system, reconnect the infrared sensor jumper
harness connector to A/C-heater control.
(4) Install the center bezel onto the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(5) Reconnect the battery negative cable.
A/C PRESSURE TRANSDUCER
DESCRIPTION
The A/C pressure transducer is a switch that is
installed on a fitting located on the refrigerant liquid
line between the receiver/drier and the expansion
valve in the right rear corner of the engine compart-
ment. An internally threaded hex fitting on the
transducer connects it to the externally threaded
Schrader-type fitting on the liquid line. A rubber
O-ring seals the connection between the transducer
and the liquid line fitting. Three terminals within a
molded plastic connector receptacle on the top of the
transducer connect it to the vehicle electrical system
through a wire lead and connector of the headlamp
and dash wire harness.
The A/C pressure transducer cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The A/C pressure transducer monitors the pres-
sures in the high side of the refrigerant system
through its connection to a fitting on the liquid line.
The transducer will change its internal resistance in
response to the pressures it monitors. The power-
train control module (PCM) provides a five volt ref-
erence signal and a sensor ground to the transducer,
then monitors the output voltage of the transducer
on a sensor return circuit to determine refrigerant
pressure. The PCM is programmed to respond to this
and other sensor inputs by controlling the operation
of the A/C compressor clutch and the radiator cooling
fan to help optimize air conditioning system perfor-
Fig. 9 A/C-Heater Control ± ATC shown, MTC typical
1 - INFRARED SENSOR CONNECTOR (ATC ONLY)
2 - INFRARED SENSOR HARNESS (ATC ONLY)
3 - A/C-HEATER CONTROL
4 - SCREW (6)
5- INSTRUMENT PANEL CENTER BEZEL
24 - 20 CONTROLS - FRONTRS
A/C HEATER CONTROL (Continued)

(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(3) Disconnect and isolate the negative battery
cable.
(4) Remove the windshield wiper module from the
vehicle (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS/WIPER MODULE - REMOVAL).
(5) Disconnect the liquid line and suction line from
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - FRONT/LIQUID
LINE - REMOVAL) and (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - FRONT/SUC-
TION LINE - REMOVAL).
(6) Disconnect the heater hoses from the heater
core tubes (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/HEATER HOSE -
REMOVAL).
(7) On LHD models, remove the one bolt that
secures the HVAC housing to the dash panel (Fig.
12).
(8) Remove the nuts that secure the HVAC hous-
ing to the dash panel in the engine compartment.(9) Remove the instrument panel from the passen-
ger compartment (Refer to 23 - BODY/INSTRU-
MENT PANEL/INSTRUMENT PANEL ASSEMBLY -
REMOVAL).
(10) Remove the floor distribution duct (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION - FRONT/FLOOR DISTRIBUTION DUCTS -
REMOVAL).
(11) Remove the bolt or bolts (depending on appli-
cation) that secure the HVAC housing to the passen-
ger compartment side of the dash panel (Fig. 13) or
(Fig. 14).
(12) Pull the HVAC housing rearward far enough
for the mounting studs to clear the dash panel and
remove the housing from the passenger compart-
ment.
DISSASEMBLY
(1) Remove the HVAC housing from the vehicle
and place it on a workbench (Refer to 24 - HEATING
& AIR CONDITIONING/DISTRIBUTION - FRONT/
HVAC HOUSING - REMOVAL).
(2) Remove the heater core tubes from the heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
REMOVAL - HEATER CORE TUBES).
(3) Remove and discard the foam seal from the
HVAC housing seal flange around the fresh air inlet
opening and the expansion valve/evaporator tube
opening.
(4) Remove the expansion valve from the evapora-
tor inlet and outlet tube fittings (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - FRONT/
EXPANSION VALVE - REMOVAL).
Fig. 12 HVAC Housing Retainers - RS Shown
1 - HVAC HOUSING
2 - DASH PANEL
3 - STUD (3 RS models, 4 RG models)
4 - NUT (3 RS models, 4 RG models)
5 - BOLT (RS only)
Fig. 13 HVAC Housing - LHD Models
1 - HVAC HOUSING
2 - BOLT
3 - BRACKET
4 - DASH PANEL
RSDISTRIBUTION - FRONT24-51
HVAC HOUSING (Continued)

(7) Reconnect the heater hoses to the heater core
tubes (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER HOSE -
INSTALLATION).
(8) Reconnect the suction line and liquid line to
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - FRONT/SUCTION
LINE - INSTALLATION) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - FRONT/
LIQUID LINE - INSTALLATION).
(9) Install the windshield wiper module (Refer to 8
- ELECTRICAL/WIPERS/WASHERS/WIPER MOD-
ULE - INSTALLATION).
(10) Reconnect the negative battery cable.
(11) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(12) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(13) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
INSTRUMENT PANEL
DEMISTER DUCTS
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel from the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the fasteners that secure the demister
ducts to the instrument panel armature.
(5) Disengage the demister ducts from the demis-
ter outlets.
(6) Remove the demister ducts from the instru-
ment panel.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the demister ducts to the instrument
panel.
(2) Engage the demister ducts to the demister out-
lets.
(3) Install the fasteners that secure the demister
ducts to the instrument panel armature.
(4) Reinstall the instrument panel into the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
24 - 54 DISTRIBUTION - FRONTRS
HVAC HOUSING (Continued)

(3) Remove the three screws that secure the rear
blower motor to the outboard side of the rear HVAC
housing (Fig. 4).
(4) Remove the rear blower motor from the rear
HVAC housing.
INSTALLATION
(1) Position the rear blower motor into the rear
HVAC housing.
(2) Install the three screws that secure the blower
motor to the rear HVAC housing. Tighten the screws
to 2 N´m (17 in. lbs.).
(3) Reconnect the rear blower motor pigtail wire
connector.
NOTE: With the Manual Temperature Control system
, the blower pigtail wire is connected to a take out
and connector of the rear HVAC wire harness. With
the Automatic Temperature Control system, the
blower pigtail wire is connected to a receptacle on
the blower motor power module.(4) Install the rear HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - INSTALLATION).
HVAC HOUSING
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(3) Disconnect and isolate the negative battery
cable.
(4) Raise and support the vehicle.
(5) Remove the nut that secures the underbody
refrigerant line sealing plate to the rear evaporator
extension line tapping plate that extends through the
rear floor panel behind the right rear wheel housing
(Fig. 5) and (Fig. 6).
(6) Disconnect the underbody refrigerant lines
from the rear evaporator extension line tapping plate
and remove and discard the O-ring seals.
(7) Install plugs in, or tape over the opened under-
body refrigerant line fittings and the evaporator
extension line sealing plate ports.
(8) Remove the nuts from the mounting studs that
secure the rear HVAC housing to the rear floor panel
behind the right rear wheel housing (Fig. 7).
(9) Lower the vehicle.
(10) Remove the right quarter trim panel and
right D-pillar trim panel from the quarter inner
panel (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - REMOVAL).
(11) Remove the rear distribution duct from the
rear HVAC housing and the rear roof duct (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION/AIR OUTLETS - REMOVAL).
(12) Disconnect the body wire harness connector
for the rear HVAC housing from the rear HVAC wire
harness connector located near the expansion valve
at the back of the housing.
Fig. 4 Rear Blower Motor
1 - REAR HVAC HOUSING
2 - REAR BLOWER MOTOR
3 - SCREW (3)
4 - BLOWER MOTOR PIGTAIL WIRE
24 - 60 DISTRIBUTION - REARRS
BLOWER MOTOR (Continued)

(10) Reconnect the body wire harness connector for
the rear HVAC housing to the rear HVAC wire har-
ness connector located near the expansion valve at
the back of the housing.
(11) Reinstall the rear distribution duct onto the
rear HVAC housing and the rear roof duct (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION/AIR OUTLETS - INSTALLATION).
(12) Reinstall the right quarter trim panel and
right D-pillar trim panel onto the quarter inner
panel (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - INSTALLATION).
(13) Raise and support the vehicle.
(14) Install the three nuts that secure the rear
HVAC housing mounting studs to the rear floor panel
behind the right rear wheel housing. Tighten the
nuts to 9 N´m (80 in. lbs.).
(15) Remove the tape or plugs from the underbody
refrigerant line fittings and both ports in the rear
evaporator extension line sealing plate.
(16) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the underbody
refrigerant line fittings.
(17) Reconnect the underbody refrigerant line seal-
ing plate to the evaporator extension line tapping
plate.
(18) Install the nut that secures the underbody
refrigerant line sealing plate to the evaporator exten-
sion line tapping plate. Tighten the nut to 23 N´m
(17 ft. lbs.).
(19) Lower the vehicle.
(20) Reconnect the battery negative cable.
(21) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(22) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(23) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
(24) Run the HVAC Cooldown test to verify proper
operation (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING).REAR FLOOR HEAT DUCT
REMOVAL
(1) Remove the trim from the right quarter inner
panel (Refer to 23 - BODY/INTERIOR/RIGHT
QUARTER TRIM PANEL - REMOVAL).
(2) Remove the two screws that secure the rear
floor heat duct to the right quarter inner panel (Fig.
9).
(3) Slide the rear floor heat duct forward far
enough to disengage it from the outlet on the front of
the rear HVAC housing.
(4) Remove the rear floor heat duct from the vehi-
cle.
INSTALLATION
(1) Align the inlet end of rear floor heat duct with
the outlet on the front of the rear HVAC housing.
(2) Slide the rear floor heat duct rearward far
enough to fully engage the inlet end of the duct with
the outlet on the rear HVAC housing.
(3) Install the two screws that secure the rear floor
heat duct to the right quarter inner panel. Tighten
the screws to 2 N´m (17 in. lbs.).
(4) Reinstall the trim onto the right quarter inner
panel (Refer to 23 - BODY/INTERIOR/RIGHT
QUARTER TRIM PANEL - INSTALLATION).
Fig. 9 Rear Floor Heat Duct
1 - REAR FLOOR HEAT DUCT
2 - REAR HVAC HOUSING OUTLET
3 - SCREW (2)
RSDISTRIBUTION - REAR24-63
HVAC HOUSING (Continued)

PLUMBING - FRONT
TABLE OF CONTENTS
page page
PLUMBING - FRONT
DESCRIPTION.........................65
OPERATION...........................65
WARNING
ENGINE COOLING SYSTEM.............65
A/C SYSTEM.........................66
CAUTION - A/C SYSTEM.................66
DIAGNOSIS AND TESTING
REFRIGERANT SYSTEM LEAKS..........67
SYSTEM CHARGE LEVEL TEST..........67
STANDARD PROCEDURE
HANDLING TUBING AND FITTINGS.......69
REFRIGERANT SYSTEM SERVICE
EQUIPMENT.........................69
REFRIGERANT SYSTEM RECOVERY......70
REFRIGERANT SYSTEM EVACUATE......70
REFRIGERANT SYSTEM CHARGE........71
A/C COMPRESSOR
DESCRIPTION
A/C COMPRESSOR....................72
HIGH PRESSURE RELIEF VALVE.........72
OPERATION
A/C COMPRESSOR....................72
HIGH PRESSURE RELIEF VALVE.........72
DIAGNOSIS AND TESTING
A/C COMPRESSOR NOISE DIAGNOSIS....72
REMOVAL
A/C COMPRESSOR....................73
A/C COMPRESSOR MOUNTING BRACKET -
2.4L ENGINE.........................74
INSTALLATION
A/C COMPRESSOR....................74
A/C COMPRESSOR MOUNTING BRACKET -
2.4L ENGINE.........................75
A/C CONDENSER
DESCRIPTION.........................75
OPERATION...........................75
REMOVAL
2.4L/3.3L/3.8L ENGINES................76
2.5L/2.8L DIESEL ENGINES..............77
INSTALLATION
2.4L/3.3L/3.8L ENGINES................77
2.5L/2.8L DIESEL ENGINES..............78
A/C DISCHARGE LINE
REMOVAL.............................79
INSTALLATION.........................80
A/C EVAPORATOR
DESCRIPTION.........................80OPERATION...........................80
REMOVAL.............................81
INSTALLATION.........................81
EXPANSION VALVE
DESCRIPTION.........................81
OPERATION...........................81
DIAGNOSIS AND TESTING
FRONT A/C EXPANSION VALVE..........82
REMOVAL.............................82
INSTALLATION.........................83
HEATER CORE
DESCRIPTION.........................83
OPERATION...........................84
REMOVAL
FRONT HEATER CORE TUBES...........84
FRONT HEATER CORE.................85
INSTALLATION
FRONT HEATER CORE TUBES...........85
FRONT HEATER CORE.................86
HEATER INLET HOSE
REMOVAL.............................86
INSTALLATION.........................87
HEATER RETURN HOSE
REMOVAL.............................88
INSTALLATION.........................89
LIQUID LINE
REMOVAL.............................89
INSTALLATION.........................91
RECEIVER / DRIER
DESCRIPTION.........................92
OPERATION...........................92
REMOVAL.............................92
INSTALLATION.........................93
REFRIGERANT
DESCRIPTION.........................93
OPERATION...........................94
REFRIGERANT OIL
DESCRIPTION.........................94
OPERATION...........................94
STANDARD PROCEDURE
REFRIGERANT OIL LEVEL..............94
SERVICE PORT VALVE CORE
DESCRIPTION.........................95
REMOVAL.............................95
INSTALLATION.........................95
SUCTION LINE
REMOVAL.............................96
INSTALLATION.........................97
24 - 64 PLUMBING - FRONTRS

PLUMBING - FRONT
DESCRIPTION
CAUTION: The system must be completely empty
before opening any fitting or connection in the
refrigeration system. Open fittings with caution
even after the system has been emptied. If any
pressure is noticed as a fitting is loosened,
retighten fitting and evacuate the system again.
The use of correct wrenches when making connec-
tions is very important. Improper wrenches or
improper use of wrenches can damage the fittings.
The internal parts of the A/C system will remain sta-
ble as long as moisture-free refrigerant and refrig-
erant oil is used. Abnormal amounts of dirt,
moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities. Before disconnecting a refrigerant line
or hose, clean the outside of the fittings thoroughly
to prevent contamination from entering the refriger-
ant system.
When opening a refrigeration system, have every-
thing you will need to repair the system ready to
minimize the amount of time the system is opened.
Cap or plug all refrigerant line fittings as soon as
they are opened. This will help prevent the entrance
of dirt and moisture. All new lines and components
should be capped or sealed until they are ready to
be used. Before connecting a refrigerant line or
hose, clean the outside of the fittings thoroughly to
prevent contamination from entering the refrigerant
system.
All tools, including the refrigerant dispensing mani-
fold, manifold gauge set and test hoses should be
kept clean and dry.
The A/C refrigerant lines and hoses are used to
carry the refrigerant between the various A/C system
components. The refrigerant lines and hoses for the
R-134a system on this vehicle consist of a barrier-
hose design with a nylon tube sandwiched between
rubber layers. The nylon tube helps to contain the
R-134a refrigerant, which has a smaller molecular
structure than R-12 refrigerant. The ends of the
refrigerant lines are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.Any kinks or sharp bends in the refrigerant lines
and hoses will reduce the capacity of the entire A/C
system and can reduce the flow of refrigerant in the
system. The radius of all bends in the flexible hose
refrigerant lines should be at least ten times the
diameter of the hose and the refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) away from the exhaust manifold(s) and
exhaust pipe(s).
OPERATION
High pressures are produced in the refrigerant sys-
tem when the A/C compressor is operating. Extreme
care must be exercised to make sure that each of the
refrigerant system connections is pressure-tight and
leak free. It is a good practice to inspect all flexible
hose refrigerant lines at least once a year to make
sure they are in good condition and properly routed.
The refrigerant lines and hoses are coupled to
other A/C system components with block-type fit-
tings. An O-ring seal, or a flat steel gasket with an
integral O-ring (dual plane seal), is used to mate the
refrigerant line fittings with A/C system components
to ensure the integrity of the refrigerant system.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.
WARNING
ENGINE COOLING SYSTEM
WARNING: THE ENGINE COOLING SYSTEM IS
DESIGNED TO DEVELOP INTERNAL PRESSURES
OF 97 TO 123 KILOPASCALS (14 TO 18 POUNDS
PER SQUARE INCH). DO NOT REMOVE OR
LOOSEN THE COOLANT PRESSURE CAP, CYLIN-
DER BLOCK DRAIN PLUGS, RADIATOR DRAIN,
RADIATOR HOSES, HEATER HOSES, OR HOSE
CLAMPS WHILE THE ENGINE COOLING SYSTEM IS
HOT AND UNDER PRESSURE. FAILURE TO
OBSERVE THIS WARNING CAN RESULT IN SERI-
OUS BURNS FROM THE HEATED ENGINE COOL-
ANT. ALLOW THE VEHICLE TO COOL FOR A
MINIMUM OF 15 MINUTES BEFORE OPENING THE
COOLING SYSTEM FOR SERVICE.
RSPLUMBING - FRONT24-65

DIAGNOSIS AND TESTING
REFRIGERANT SYSTEM LEAKS
WARNING: R-134a SERVICE EQUIPMENT OR VEHI-
CLE A/C SYSTEM SHOULD NOT BE PRESSURE
TESTED OR LEAK TESTED WITH COMPRESSED
AIR. MIXTURE OF AIR and R-134a CAN BE COMBUS-
TIBLE AT ELEVATED PRESSURES. THESE MIX-
TURES ARE POTENTIALLY DANGEROUS AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
AVOID BREATHING A/C REFRIGERANT AND LUBRI-
CANT VAPOR OR MIST. EXPOSURE MAY IRRITATE
EYES, NOSE AND THROAT. USE ONLY APPROVED
SERVICE EQUIPMENT MEETING SAE REQUIRE-
MENTS TO DISCHARGE R-134a SYSTEM. IF ACCI-
DENTAL SYSTEM DISCHARGE OCCURS, VENTILATE
WORK AREA BEFORE RESUMING SERVICE.
If the A/C system is not cooling properly, determine
if the refrigerant system is fully charged with R-134a
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT - DIAGNO-
SIS AND TESTING - REFRIGERANT SYSTEM
CHARGE LEVEL). If while performing this test A/C
liquid line pressure is less than 345 kPa (50 psi) pro-
ceed to System Empty procedure. If liquid line pres-
sure is greater than 345 kPa (50 psi) proceed to
System Low procedure. If the refrigerant system is
empty or low in refrigerant charge, a leak at any line
fitting or component seal is likely. A review of the fit-
tings, lines and components for oily residue is an
indication of the leak location.
To detect a leak in the refrigerant system, perform
one of the following procedures as indicated by the
results of the refrigerant system charge level test.
SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approx. 28 in Hg.) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - FRONT/REFRIGERANT - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM EVACUATE).
Determine if the system holds a vacuum for 15 min-
utes. If vacuum is held, a leak is probably not
present. If system will not maintain vacuum level,
proceed with this procedure.
(2) Prepare a 0.284 Kg. (10 oz.) refrigerant charge
to be injected into the system.
(3) Connect and dispense 0.284 Kg. (10 oz.) of
refrigerant into the evacuated refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT - STANDARD
PROCEDURE - REFRIGERANT SYSTEM CHARGE).
(4) Proceed to the SYSTEM LOW procedures.SYSTEM LOW
(1) Position the vehicle in a wind-free work area.
This will aid in detecting small leaks.
(2) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes with the system
set to the following:
²Transaxle in Park
²Engine idling
²Rear A/C Off (if equipped)
²A/C controls set to 100 percent outside air
²Blower switch in the highest speed position
²A/C in the ON position
²Front windows open
CAUTION: A leak detector designed for R-12 refrig-
erant (only) will not detect leaks in a R-134a refrig-
erant system.
(3) Shut off the vehicle and wait 2 to 7 minutes.
Then use an Electronic Leak Detector that is
designed to detect R-134a type refrigerant and search
for leaks. Fittings, lines, or components that appear
to be oily usually indicates a refrigerant leak. To
inspect the evaporator core for leaks, insert the leak
detector probe into the drain tube opening or a heat
duct. A R-134a dye is available to aid in leak detec-
tion, use only DaimlerChrysler approved refrigerant
dye.
SYSTEM CHARGE LEVEL TEST
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
NOTE: Always refer to the underhood HVAC Speci-
fication Label for the refrigerant fill specification of
the vehicle being serviced.
The procedure that follows should be used to deter-
mine whether the refrigerant system contains the
proper refrigerant charge. Symptoms of an improper
refrigerant charge (low) include: poor air conditioner
performance, fog emitted from the air conditioner
outlets, a hissing sound from the expansion valve/
evaporator area. There are two different methods
with which the refrigerant charge level may be
tested:
1. Using a DRBIIItscan tool, a thermocouple and
the Charge Determination Chart (Fig. 1). Refer to
the appropriate diagnostic information.
RSPLUMBING - FRONT24-67
PLUMBING - FRONT (Continued)