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)
2. Using a manifold gauge set, a thermocouple and
the Charge Determination Chart (Fig. 1).
A temperature probe is required to measure liquid
line temperature. The clamp-on, Type K thermocou-
ple temperature probe used in this procedure is
available through the DaimlerChrysler Professional
Service Equipment (PSE) program. This probe (PSE
#66-324-0014 or #80PK-1A) is compatible with tem-
perature-measuring instruments that accept Type K
thermocouples, and have a miniature connector
input. Other temperature probes are available
through aftermarket sources; however, all references
in this procedure will reflect the use of the probe
made available through the PSE program.
In order to use the temperature probe, a digital
thermometer will also be required. If a digital ther-
mometer is not available, an adapter is available
through the PSE program that will convert any stan-
dard digital multimeter into a digital thermometer.
This adapter is designed to accept any standard Type
K thermocouple. If a digital multimeter is not avail-
able, this tool is also available through the PSE pro-
gram.NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.
(1) Remove the caps from the refrigerant system
service ports and attach a manifold gauge set or a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 to the refriger-
ant system.
(2) Attach a clamp-on thermocouple to the liquid
line. The thermocouple must be placed as close to the
A/C pressure transducer as possible to accurately
observe liquid line temperature.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run at idle under the following condi-
tions for five minutes.
(a) Front windows are open.
(b) Transaxle in Park.
(c) Front heater-A/C controls set to outside air,
full cool, panel mode, blower high, and compressor
engaged.
(d) If the vehicle is so equipped, the rear heater-
A/C controls must be set to full cool and blower
high.
Fig. 1 Charge Determination Chart, Ambient Test Condition 85ÉF
24 - 68 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)
(4) Open both the suction and discharge valves,
then open the charge valve to allow the heated
refrigerant to flow into the system.
(5) When the transfer of refrigerant has stopped,
close both the suction and discharge valves.
(6) If all of the refrigerant charge did not transfer
from the dispensing device, open all of the windows
in the vehicle and set the heater-air conditioner con-
trols so that the compressor is engaged and the
blower motor is operating at its lowest speed setting.
Run the engine at a steady high idle (about 1400
rpm). If the compressor will not engage, test the com-
pressor clutch control circuit and repair as required.
(7) Open the suction valve to allow the remaining
refrigerant to transfer to the refrigerant system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH PRESSURE) VALVE AT THIS TIME.
(8) Close the suction valve and test the system
performance. (Refer to 24 - HEATING & AIR CON-
DITIONING - STANDARD PROCEDURE - A/C PER-
FORMANCE TEST).
(9) Disconnect the charging station and manifold
gauge set from the refrigerant system service ports.
(10) Reinstall the caps onto the refrigerant system
service ports.
(11) Run the HVAC Control Cooldown test to ver-
ify proper operation(Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING).
A/C COMPRESSOR
DESCRIPTION
A/C COMPRESSOR
Vehicles equipped with the 2.4L gasoline, 2.5L die-
sel, 2.8L diesel and 3.3L gasoline engines with the
front heating-A/C system only, use the Denso 10S17
A/C compressor. Vehicles equipped with the 3.3L and
the 3.8L gasoline engines with the optional rear heat-
ing-A/C system use the Denso 10S20 A/C compressor.
Both A/C compressors include an integral high pres-
sure relief valve. The A/C compressor is secured to a
mounting bracket on the 2.4L gasoline engine and
directly to the cylinder block on the 2.5L diesel, 2.8L
diesel, 3.3L gasoline and 3.8L gasoline engines.
HIGH PRESSURE RELIEF VALVE
A high pressure relief valve is located on the rear
of the A/C compressor. This mechanical valve is
designed to vent refrigerant from the A/C system to
protect against damage to the compressor and other
system components, caused by condenser air flow
restriction or an overcharge of refrigerant.
OPERATION
A/C COMPRESSOR
The A/C compressor is driven by the engine
through an electric clutch, drive pulley and belt
arrangement. The compressor is lubricated by refrig-
erant oil that is circulated throughout the refrigerant
system with the refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor. The compressor
pumps the high-pressure refrigerant vapor to the
condenser through the compressor discharge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley and clutch
coil are available for service.
HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes
when a minimum discharge pressure of 2756 kPa
(400 psi) is reached.
The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean that the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING
A/C COMPRESSOR NOISE DIAGNOSIS
Excessive noise while the air conditioning compres-
sor is operating can be caused by loose compressor
mounts, a loose compressor clutch, or high operating
pressures in the refrigerant system. Verify compres-
sor drive belt condition, proper compressor mounting,
correct refrigerant charge level, and compressor head
pressure before compressor repair is performed.
With the close tolerances within the compressor, it
is possible to experience a temporary lockup. The
longer the compressor is inactive, the more likely the
condition is to occur. This condition is the result of
normal refrigerant migration within the refrigerant
system caused by ambient temperature changes. The
refrigerant migration may wash the refrigerant oil
out of the compressor.
24 - 72 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)
DIAGNOSIS AND TESTING
FRONT A/C EXPANSION VALVE
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: The A/C expansion valve should only be
tested following testing of the A/C compressor.
NOTE: Liquid CO
2is required to test the A/C expan-
sion valve. This material is available from most
welding supply facilities. Liquid CO
2is also avail-
able from companies which service and sell fire
extinguishers.
When testing the A/C expansion valve, the work
area and the vehicle temperature must be 21É to 27É
C (70É to 85É F). To test the expansion valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set the A/C-heater controls so that the A/C
compressor is operating, the temperature control is
in the highest temperature position, the mode door is
directing the output to the floor outlets, and the
blower motor is operating at the highest speed set-
ting.
(4) Start the engine and allow it to idle. After the
engine has reached normal operating temperature,
allow the passenger compartment to heat up. This
will create the need for maximum refrigerant flow
into the A/C evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 kPa to
1655 kPa (140 psi to 240 psi). The suction (low pres-
sure) gauge should read 138 kPa to 207 kPa (20 psi
to 30 psi). If OK, go to Step 6. If not OK, replace the
faulty A/C expansion valve.
WARNING:
PROTECT THE SKIN AND EYES FROM EXPOSURE
TO LIQUID CO
2OR PERSONAL INJURY CAN
RESULT.
(6) If the suction (low pressure) gauge reads
within the specified range, freeze the A/C expansion
valve for 30 seconds using liquid CO
2or another suit-able super-cold material.Do not spray R-134a or
R-12 refrigerant on the A/C expansion valve for
this test.The suction (low pressure) gauge reading
should drop by 69 kPa (10 psi). If OK, go to Step 7 If
not OK, replace the faulty A/C expansion valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 138 kPa to 207 kPa (20 psi to 30 psi). If not
OK, replace the faulty A/C expansion valve.
(8) When expansion valve testing is complete, test
the overall A/C system performance (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
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) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
(5) Disconnect the wire harness connector from the
A/C pressure transducer (Fig. 16).
(6) Remove the screw that secures the front liquid
line rear section fitting to the top of the receiver/
drier.
(7) Disconnect the liquid line fitting from the
receiver/drier outlet port.
(8) Remove the seal from the liquid line fitting and
discard.
(9) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(10) Remove the nut that secures the suction line
and liquid line fittings to the stud on the A/C expan-
sion valve.
(11) Disconnect the suction line and liquid line fit-
tings from the A/C expansion valve and move the
lines out of the way.
(12) Remove the seals from the suction line and
liquid line fittings and discard.
24 - 82 PLUMBING - FRONTRS
EXPANSION VALVE (Continued)
heater core inlet and outlet ports. Removable heater
core tubes attach to the ports by use of a sealing
plate secured with a screw to the heater core tank.
This removable heater core tube arrangement allows
the heater core to be serviced without removing the
HVAC housing from the vehicle.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend door
allows control of the heater output air temperature
by regulating the amount of air that is flowing
through the heater core within the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
FRONT HEATER CORE TUBES
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) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the heater hoses from the heater
core tubes (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/HEATER INLET HOSE -
REMOVAL) and (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/HEATER RETURN
HOSE - REMOVAL).(4) Remove the silencer from beneath the driver
side end of the instrument panel.
NOTE: Take the proper precautions to protect the
carpeting below the heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to clean up any spills.
(5) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 17).
(6) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(7) Install plugs in, or tape over the opened heater
core tube fittings and both heater core ports.
(8) Pull both heater core tubes simultaneously
slightly away from the distribution housing and rear-
ward far enough to disengage the engine compart-
ment ends of the tubes from the dash panel seal.
(9) Remove the heater core tubes and sealing plate
as a unit from beneath the instrument panel.
(10) Use absorbent toweling to clean up any
engine coolant spills from the preceding operation.
Fig. 17 Heater Core Tubes - LHD Shown, RHD
Typical
1 - SEAL
2 - HEATER CORE TUBES
3 - SCREW
4 - HEATER CORE
5 - DISTRIBUTION HOUSING
6 - SEALING PLATE
24 - 84 PLUMBING - FRONTRS
HEATER CORE (Continued)
(8) Disconnect the A/C liquid line from the A/C
condenser and remove and discard the O-ring seal
and gasket.
(9) Install plugs in, or tape over the opened liquid
line fitting and the condenser outlet port.
(10) Disengage the retainer that secures the liquid
line routing clip to the top of the right frame rail
ahead of the front strut tower in the engine compart-
ment (Fig. 28).
(11) Remove the bolt that secures the front section
of the A/C liquid line to the receiver/drier.
(12) Disconnect the A/C liquid line from the receiv-
er/drier and remove and discard the O-ring seal.
(13) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier inlet port.
(14) Remove the front section of the A/C liquid line
from the engine compartment.
REAR SECTION
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
(5) Remove the A/C pressure transducer (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER -
REMOVAL).(6) If equipped, remove the nut that secures the
A/C ground strap to the weld stud on the top of the
right front strut tower (Fig. 28).
(7) If equipped, remove the A/C ground strap eye-
let terminal connector from the weld stud.
(8) Remove the bolt that secures the rear section
of the A/C liquid line to the receiver/drier.
(9) Disconnect the A/C liquid line from the receiv-
er/drier and remove and discard the O-ring seal.
(10) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(11) Remove the nut that secures the A/C suction
line and the A/C liquid line to the A/C expansion
valve.
(12) Disconnect the A/C suction line and the A/C
liquid line from the A/C expansion valve and remove
and discard the O-ring seals.
(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(14) On RHD models, remove the rear section of
the A/C liquid line from the retaining bracket located
at the top of the dash panel
Fig. 27 A/C Condenser Connections
1 - A/C CONDENSER
2 - A/C DISCHARGE LINE
3 - A/C LIQUID LINE
4 - NUT (2)Fig. 28 A/C Liquid Line - LHD Shown, RHD Typical
1 - A/C GROUND STRAP (IF EQUIPPED)
2 - NUT (IF EQUIPPED)
3 - WELD STUD (IF EQUIPPED)
4 - A/C PRESSURE TRANSDUCER
5 - WELD STUD (2)
6 - A/C EXPANSION VALVE
7 - A/C LIQUID LINE (REAR SECTION)
8 - LIQUID LINE EXTENSION (REAR A/C ONLY)
9 - NUT (2)
10 - RECEIVER/DRIER
11 - ROUTING CLIP
12 - A/C LIQUID LINE (FRONT SECTION)
24 - 90 PLUMBING - FRONTRS
LIQUID LINE (Continued)
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(8) Reconnect the A/C liquid line to the receiver/
drier.
(9) Install the bolt that secures the A/C liquid line
to the receiver/drier. Tighten the bolt to 11 N´m (97
in. lbs.).
(10) If equipped, reinstall the A/C ground strap
eyelet terminal connector onto the weld stud on the
top of the right front strut tower (if equipped).
(11) If equipped, install the nut that secures the
A/C ground strap to the weld stud. Tighten the nut
to 12 N´m (106 in. lbs.)
(12) Install the A/C pressure transducer (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER - INSTAL-
LATION).
(13) Connect the drain tube to the wiper module
drain on the right side of the engine compartment.
(14) Install the air cleaner housing into the right
side of the engine compartment.
(15) On RHD models, install the liquid line into
the retaining bracket located at the top of the dash
panel.
(16) If the vehicle is equipped with the optional
rear heating-A/C system, go to Step 17. If the vehicle
does not have the optional rear heating-A/C system,
go to Step 23.
(17) Raise and support the vehicle.
(18) Remove the tape or plugs from the A/C liquid
line extension fitting and the underbody liquid line
fitting.
(19) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the underbody liquid
line fitting.
(20) Connect the A/C liquid line extension fitting
to the underbody liquid line fitting. Tighten the fit-
tings to 23 N´m (17 ft. lbs.).
(21) Install a new tie strap just forward of the con-
nections between the underbody plumbing and the
engine compartment plumbing for the rear heating-
A/C system.
(22) Lower the vehicle.
(23) Reconnect the negative battery cable.
(24) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(25) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).RECEIVER / DRIER
DESCRIPTION
The receiver/drier is mounted in a bracket secured
to the right front strut tower in the engine compart-
ment. The receiver/drier is connected between the
front and rear sections of the liquid line between the
condenser outlet and the evaporator inlet. The receiv-
er/drier cannot be repaired. If the receiver/drier is
faulty or damaged, or if the refrigerant system has
been contaminated or left open to the atmosphere for
an indeterminable period or if the A/C compressor
has failed, it must be replaced.
OPERATION
The receiver/drier performs a filtering action to
prevent foreign material in the refrigerant from con-
taminating the expansion valve. Desiccant inside the
receiver/drier canister absorbs any moisture which
may have entered and become trapped within the
refrigerant system. In addition, during periods of
high demand air conditioner operation, the receiver/
drier acts as a reservoir to store surplus refrigerant.
Refrigerant enters the receiver/drier as a high-pres-
sure, low temperature liquid.
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) Remove the air cleaner housing from the right
side of the engine compartment.
(3) Remove the bolt that secures the liquid line
front section fitting to the top of the receiver/drier
(Fig. 30).
(4) Disconnect the liquid line fitting from the
receiver/drier inlet port.
(5) Remove the O-ring seal from the liquid line fit-
ting and discard.
(6) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier inlet port.
24 - 92 PLUMBING - FRONTRS
LIQUID LINE (Continued)
(9) Remove the evaporator line extension seal
plate from the expansion valve stud.
(10) Remove the evaporator line extension from
the expansion valve and the rear HVAC housing
base.
(11) Remove the seals from the evaporator line
extension fittings and discard.
(12) Install plugs in, or tape over the opened evap-
orator line extension fittings and both expansion
valve ports.
INSTALLATION
REAR A/C EVAPORATOR
NOTE: If the rear A/C evaporator is being replaced,
add 50 milliliters (1.7 fluid ounces) of refrigerant oil
to the refrigerant system. Use only refrigerant oil of
the type recommended for the A/C compressor in
the vehicle.
(1) Carefully lower the rear A/C evaporator and its
foam wrap into the lower half of the rear HVAC
housing.
(2) Position the upper half of the rear HVAC hous-
ing onto the lower half.
(3) Install the three metal spring clips that secure
the upper half of the rear HVAC housing to the lower
half.
(4) Install the three screws that secure the upper
half of the rear HVAC housing to the lower half.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Install the rubber grommet that seals the evap-
orator inlet and outlet tubes to the rear HVAC hous-
ing near the expansion valve.
(6) Reinstall the rear expansion valve onto the
rear A/C evaporator (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EXPANSION
VALVE - INSTALLATION).
(7) Reinstall the rear evaporator extension line
onto the expansion valve (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - REAR/EVAPO-
RATOR - INSTALLATION - EVAPORATOR EXTEN-
SION LINE).
(8) Reinstall the rear HVAC housing into the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION - REAR/REAR HEATER-A/C
HOUSING - INSTALLATION).
REAR A/C EVAPORATOR LINE EXTENSION
(1) Remove the tape or plugs from the evaporator
line extension fittings and both expansion valve
ports.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
line extension fittings.(3) Position the evaporator line extension to the
expansion valve and the rear HVAC housing base.
(4) Position the evaporator line extension seal
plate over the expansion valve stud.
(5) Install the nut that secures the evaporator line
extension seal plate to the expansion valve stud.
Tighten the nut to 23 N´m (17 ft. lbs.).
(6) Position the expansion valve bracket over the
expansion valve stud.
(7) Install the two screws that secure the expan-
sion valve bracket to the lower rear HVAC housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(8) Install the nut that secures the expansion
valve bracket to the expansion valve stud. Tighten
the nut to 23 N´m (17 ft. lbs.).
(9) Carefully restore the expansion valve foam
insulator wrap back around the expansion valve.
(10) Position the plate that captures and seals the
evaporator line extension onto the rear HVAC hous-
ing base.
(11) Install the screw that secures the capture
plate to the base of the rear HVAC housing. Tighten
the screw to 2 N´m (17 in. lbs.).
(12) Install the rear HVAC housing into the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING -
INSTALLATION).
A/C EXPANSION VALVE
DESCRIPTION
The rear ªHº valve-type thermal expansion valve
(TXV) is located at the rear of the rear HVAC hous-
ing between the evaporator line extension and the
evaporator coil. High-pressure, low temperature liq-
uid refrigerant from the liquid line passes through
the expansion valve orifice, converting it into a low-
pressure, low-temperature mixture of liquid and gas
before it enters the evaporator coil.
OPERATION
A mechanical sensor in the expansion valve control
head monitors the temperature and pressure of the
refrigerant leaving the evaporator coil through the
suction line, and adjusts the orifice size at the liquid
line to let the proper amount of refrigerant into the
evaporator coil to meet the vehicle cooling require-
ments. Controlling the refrigerant flow through the
evaporator ensures that none of the refrigerant leav-
ing the evaporator is still in a liquid state, which
could damage the compressor.
The rear A/C expansion valve cannot be adjusted
or repaired and, if faulty or damaged, it must be
replaced.
24 - 100 PLUMBING - REARRS
A/C EVAPORATOR (Continued)