2005 MERCEDES-BENZ SPRINTER engine

(2) Open the low and high side valves and start
the charging station vacuum pump. When the suc-
tion gauge reads 88 kPa (26 in. Hg.) vacuum or
greater, close all of the valves and turn off the vac-
uum pump.
(a) If the refrigerant system fails to reach the
specified vacuum, the system has a leak that must
be corrected. (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - DIAGNOSIS AND
TESTING - REFRIGERANT SYSTEM LEAKS)
(b) If the refrigerant system maintains the spec-
ified vacuum for five minutes, restart the vacuum
pump, open the suction and discharge valves and
evacuate the system for an additional ten minutes.
(3) Close all of the valves, and turn off the charg-
ing station vacuum pump.
(4) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
CAUTION: A small amount of refrigerant oil is
removed from the A/C system each time the refrig-
erant system is recovered and evacuated. Before
charging the A/C system, you MUST replenish any
oil lost during the recovery process. Refer the
equipment manufacturer instructions for more infor-
mation.
After the refrigerant system has been tested for
leaks and evacuated, a refrigerant charge can be
injected into the system. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - SPECIFICA-
TIONS - CHARGE CAPACITY)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
PARTIAL CHARGE METHOD
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
The partial charge method is used to add a partial
charge to a refrigerant system that is low on refrig-
erant. To perform this procedure the evaporator inlet
and outlet tube temperatures are measured. The
temperature difference is measured with a tempera-
ture meter with one or two clamp-on thermocouple
probes. The difference between the evaporator inlet
and outlet tube temperatures will determine the
amount of refrigerant needed.
Before adding a partial refrigerant charge, check
for refrigerant system leaks. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - DIAGNOSIS
AND TESTING - REFRIGERANT SYSTEM LEAKS)
If a leak is found, make the necessary repairs before
attempting a full or partial refrigerant charge.
(1) Attach a manifold gauge set to the refrigerant
system service ports.
(2) Attach the two clamp-on thermocouple probes
to the inlet and outlet tubes of the evaporator coil.
²If a single thermocouple probe is used, attach
the probe to the evaporator inlet tube just before the
collar of the refrigerant line connector fitting. The
probe must make contact with the bottom surface of
the evaporator inlet tube.
²If dual thermocouple probes are used, attach
probe 1 to the evaporator inlet tube, and probe 2 to
the evaporator outlet tube. Attach both probes to the
evaporator tubes just before the collar of the refrig-
erant line connector fittings. The probes must make
contact with the bottom surfaces of the evaporator
inlet and outlet tubes.
(3) Open all of the windows or doors of the passen-
ger compartment.
(4) Set the A/C button on the A/C Heater controls
to the on position, the temperature control knob in
the full cool position, select Recirculation Mode, and
place the blower motor switch in the highest speed
position.
(5) Start the engine and hold the engine idle speed
at 1,000 rpm. Allow the engine to warm up to normal
operating temperature.
(6) The compressor clutch may cycle, depending
upon ambient temperature, humidity, and the refrig-
erant system charge level.
(7) Hold the engine idle speed at 1,000 rpm.
(8) Allow three to five minutes for the refrigerant
system to stabilize, then record the temperatures of
the evaporator inlet and outlet tubes.
24 - 48 PLUMBINGVA
PLUMBING (Continued)

²If a single probe is used, record the temperature
of the evaporator inlet tube. Then remove the probe
from the inlet tube and attach it to the evaporator
outlet tube just before the collar of the refrigerant
line connector fitting. The probe must make contact
with the bottom surface of the evaporator outlet tube.
Allow the thermocouple and meter time to stabilize,
then record the temperature of the evaporator outlet
tube. Subtract the inlet tube temperature reading
from the outlet tube temperature reading.
²If dual probes are used, record the temperatures
of both the evaporator inlet and outlet tubes. Then
subtract the inlet tube temperature reading from the
outlet tube temperature reading.(9) If the measured temperature differential is
higher than 22É C to 26É C (40É F to 47É F), add 0.4
kilograms (14 ounces) of refrigerant.
(10) Allow three to five minutes for the refrigerant
system to stabilize, then take a second set of thermo-
couple measurements. Record the temperature differ-
ence to determine if an additional charge is required.
(11) Record the compressor discharge pressure. If
the reading is higher than the pressure shown in the
Compressor Discharge Pressure Chart, the system
could be overcharged. If the reading is equal to, or
lower, than the pressure shown in the chart, continue
with this procedure.
Compressor Discharge Pressure Chart
Ambient
Temperature16ÉC
(60ÉF)21ÉC
(70ÉF)27ÉC
(80ÉF)32ÉC
(90ÉF)38ÉC
(100ÉF)43ÉC
(110ÉF)
Compressor
Discharge
Pressure1378 kPa
(200 psi)1516 kPa
(220 psi)1723 kPa
(250psi)1930 kPa
(280 psi)2206 kPa
(320 psi)2413 kPa
(350 psi)
(12)EXAMPLE:The ambient temperature is 21É
C (70É F). The evaporator inlet tube temperature is
12É C (54É F) and the evaporator outlet tube temper-
ature is 10É C (50É F). Subtract the inlet tube tem-
perature from the outlet tube temperature. The
difference is -2É C (-4É F). With a -2É C (-4É F) tem-
perature differential at 21É C (70É F) ambient tem-
perature, the system is fully charged.
(13) Add enough refrigerant to bring the refriger-
ant system up to a full charge.
(14) Remove the jumper wire from the low pres-
sure cycling clutch switch wire harness connector
and plug the connector back into the switch.
SPECIFICATIONS
CHARGE CAPACITY
Always refer to the underhood HVAC Specification
Tag for the latest fill specification for the model being
serviced.
A/C COMPRESSOR
DESCRIPTION
The air conditioning system uses a Nippondenso
7SBU16C double-acting, variable swash plate-type
compressor on all models. This compressor has a
label identifying the use of R-134a refrigerant and
both the suction and discharge ports located on the
cylinder head.
OPERATION
The compressor is driven by the engine through an
electric clutch, drive pulley and belt arrangement.
The compressor is lubricated by refrigerant 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, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley, and coil, are
available for service.
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
VAPLUMBING 24 - 49
PLUMBING (Continued)

Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and pulley are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
to be certain that the discharge pressure does not
exceed 2760 kPa (400 psi).
(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which can
cause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAU-
TION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(5) If the noise is from opening and closing of the
high pressure relief valve, reclaim, evacuate, and
recharge the refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT RECOVERY)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)If the high pressure relief valve still
does not seat properly, replace the a/c compressor.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C COMPRESSOR - REMOVAL)
(6) If the noise is from liquid slugging on the suc-
tion line, check the refrigerant oil level and the
refrigerant system charge. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/REFRIGER-ANT OIL - STANDARD PROCEDURE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
SPECIFICATIONS - CHARGE CAPACITY).
(7) If the noise continues, replace the compressor
and repeat Step 1.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect the negative battery cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the accessory drive belt from the com-
pressor clutch (Fig. 2).
(4) Remove the bolt that secures the suction line
fitting to the top of the compressor.
(5) Disconnect the suction line fitting from the
compressor suction port.
(6) Remove the seal from the suction line fitting
and discard.
(7) Install plugs in, or tape over the opened suc-
tion line fitting and the compressor suction port.
(8) Remove the bolt that secures the discharge line
fitting to the top of the compressor.
(9) Disconnect the discharge line fitting from the
compressor discharge port.
(10) Remove the seal from the discharge line fit-
ting and discard.
(11) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(12) Disconnect the engine wire harness connector
for the compressor clutch coil from the coil pigtail
wire connector on the top of the compressor.
(13) Raise the vehicle on a hoist.
(14) Support the compressor and remove the three
compressor mounting bolts.
(15) Remove the compressor from the engine com-
partment.
NOTE: If a replacement compressor is being
installed, be certain to drain and measure the refrig-
erant oil contained in the removed compressor.
This will determine how much oil the replacement
compressor must contain before it is installed
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - STANDARD PRO-
CEDURE).
24 - 50 PLUMBINGVA
A/C COMPRESSOR (Continued)

INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
CAUTION: Check the oil level before installing the
new compressor (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/REFRIGERANT OIL -
STANDARD PROCEDURE).
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. 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.
(1) Position the A/C compressor in the engine com-
partment and loosely install the three compressor
retaining bolts. Tighten the bolts using the following
sequence to 20 N´m (15 ft. lbs.).
²The upper bolt at the front of the compressor.
²The lower bolt at the front of the compressor.
²The bolt at the rear of the compressor.
(2) Lower the vehicle.
(3) Connect the wire harness connector to the com-
pressor clutch.
(4) Remove plugs or tape from the discharge line
fitting and the compressor discharge port.
(5) Lubricate a new rubber o-ring seal with clean
refrigerant oil and install the seal onto the discharge
line fitting.
Fig. 2 2.7L Diesel Compressor-RHD (LHD typical)
1 - SUCTION LINE MOUNTING SCREW
2 - SUCTION LINE TO H-BLOCK
3 - H-BLOCK
4 - RECEIVER DRIER
5 - LIQUID LINE SERVICE PORT6 - LIQUID LINE AND RECEIVER DRIER
7 - A/C COMPRESSOR
8 - A/C COMPRESSOR DRIVE BELT
9 - RADIATOR - CONDENSOR ASSEMBLY
VAPLUMBING 24 - 51
A/C COMPRESSOR (Continued)

(6) Connect the discharge line fitting to the com-
pressor discharge port.
(7) Install the bolt that secures the discharge line
fitting to the top of the compressor. Tighten the bolt
to 23 N´m (17 ft. lbs.).
(8) Remove plugs or tape from the suction line fit-
ting and the compressor suction port.
(9) Lubricate a new rubber o-ring seal with clean
refrigerant oil and install the seal onto the suction
line fitting.
(10) Connect the suction line fitting to the com-
pressor suction port.
(11) Install the bolt that secures the suction line
fitting to the top of the compressor. Tighten the bolt
to 23 N´m (17 ft. lbs.).
(12) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(13) Reconnect the negative battery cable.
(14) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(15) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
A/C CONDENSER
DESCRIPTION
The condenser is located in the air flow in front of
the engine cooling radiator. The condenser is a heat
exchanger that allows the high-pressure refrigerant
gas being discharged by the compressor to give up its
heat to the air passing over the condenser fins.
OPERATION
When the refrigerant gas gives up its heat, it con-
denses. When the refrigerant leaves the condenser, it
has become a high-pressure liquid refrigerant. The
volume of air flowing over the condenser fins is crit-
ical to the proper cooling performance of the air con-
ditioning system. Therefore, it is important that
there are no objects placed in front of the radiator
grille openings in the front of the vehicle or foreign
material on the condenser fins that might obstruct
proper air flow. Also, any factory-installed air seals or
shrouds must be properly reinstalled following radia-
tor or condenser service.
The condenser cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the front fascia.
(4) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(5) Remove the headlamps from their mounts.
(6) Remove the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(7) Disconnect the liquid line fitting from the con-
denser outlet port (Fig. 3).
(8) Remove the seal from the liquid line fitting and
discard.
(9) Install plug in, or tape over the opened liquid
line fitting and the condenser outlet port.
(10) Disconnect the discharge line fitting from the
condenser inlet port.
(11) Remove the seal from the discharge line fit-
ting and discard.
(12) Install plug in, or tape over the opened dis-
charge line fitting and the condenser inlet port.
(13) Disconnect the wire harness connector from
the auxiliary fan.
(14) Remove the auxiliary fan and upper bracket
assembly.
(15) Remove the auxiliary fan lower bracket
retainers and bracket.
(16) Remove the four condenser retaining screws.
(17) Carefully remove the condenser from the vehi-
cle.
INSTALLATION
NOTE: If the condenser is being replaced, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Carefully position the condenser in the vehicle.
(2) Install the four condenser retaining screws.
Tighten the screws to 2 N´m (17 in. lbs.).
24 - 52 PLUMBINGVA
A/C COMPRESSOR (Continued)

(12) Disconnect the discharge line from the retain-
ing clip and remove the discharge line from the vehi-
cle.
INSTALLATION
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
(1) Position the discharge line into the engine com-
partment.
(2) Remove the tape or plugs from the compressor
discharge port and the discharge line fitting.
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(4) Connect the discharge line fitting to the com-
pressor discharge port on the top of the compressor.(5) Install the bolt that secures the discharge line
fitting to the compressor. Tighten the bolt to 23 N´m
(17 ft. lbs.).
(6) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(8) Connect the discharge line fitting to the con-
denser inlet port.
(9) Install the nut that secures the discharge line
fitting to the condenser. Tighten the nut to 33 N´m
(24 ft. lbs.).
(10) Install the grille(Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION).
(11) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(12) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(13) Reconnect the negative battery cable.
A/C EVAPORATOR
DESCRIPTION
The evaporator is located in the heater housing,
behind the instrument panel. The evaporator is posi-
tioned in the housing so that all air that enters the
housing must pass over the fins of the evaporator
coils before it is distributed through the system ducts
and outlets. However, air passing over the evaporator
coil fins will only be conditioned when the compres-
sor is engaged and refrigerant is circulating through
the evaporator coil tubes.
OPERATION
Refrigerant enters the evaporator from the expan-
sion valve as a low-temperature, low-pressure liquid.
As air flows over the fins of the evaporator, the
humidity in the air condenses on the fins, and the
heat from the air is absorbed by the refrigerant. Heat
absorption causes the refrigerant to boil and vapor-
ize. The refrigerant becomes a low-pressure gas
before it leaves the evaporator.
The evaporator cannot be repaired and, if faulty or
damaged, it must be replaced.
Fig. 4 A/C Compressor - Refrigerant Lines
1 - A/C COMPRESSOR
2 - O-RING SEAL
3 - SUCTION LINE
4 - BOLT
5 - RETAINING CLIP
6 - BOLT
7 - DISCHARGE LINE
8 - O-RING SEAL
24 - 54 PLUMBINGVA
A/C DISCHARGE LINE (Continued)

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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Remove the heater housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the heater housing to access the
evaporator (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING - DIS-
ASSEMBLY).
(3) Lift the evaporator out of the lower half of the
heater housing (Fig. 5).
INSTALLATION
(1) Install the evaporator coil into the bottom half
of the heater housing.
(2) Assemble the heater housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the heater housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
NOTE: If the evaporator is being replaced, add 60
milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system.
A/C EXPANSION VALVE
DESCRIPTION
The ªHº valve type thermal expansion valve (TXV)
is mounted in the engine compartment between the
liquid and suction lines and the evaporator.
The expansion valve is a factory calibrated unit
and cannot be adjusted or repaired. If faulty or dam-
aged, the expansion valve must be replaced.
OPERATION
High-pressure, high temperature liquid 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. A thermal sensor in the
expansion valve monitors the temperature 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 to meet the vehicle cooling requirements.
Controlling the refrigerant flow through the evapora-
Fig. 5 Heater Housing
1 - SCREW (12)
2 - HEATER HOUSING COVER
3 - EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
4 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - HEATER HOUSING
8 - WIRING HARNESS
9 - BOLT (3)
10 - HEATER CORE
11 - HEATER CORE TUBE ASSEMBLY
12 - HEATER CORE TUBE GASKET
13 - HEATER CORE TUBE O-RING SEAL (2)
VAPLUMBING 24 - 55
A/C EVAPORATOR (Continued)

tor ensures that none of the refrigerant leaving the
evaporator is still in a liquid state, which could cause
damage to the compressor.
DIAGNOSIS AND TESTING - A/C EXPANSION
VALVE
The expansion valve is located on the engine side
of the dash panel near the shock tower.
The expansion valve can fail in three different
positions (open, closed or restricted).
In an Open Position: this will result in a noisy
compressor or no cooling. The cause can be broken
spring, broken ball or excessive moisture in the A/C
system. If the spring or ball are found to be defective,
replace the expansion valve. If excessive moisture is
found in the A/C system, recycle the refrigerant.
In a Closed Position: There will be low suction
pressure and no cooling. This may be caused by a
failed power dome or excessive moisture in the A/C
system. If the power dome on the expansion valve is
found to be defective replace the expansion valve. If
excessive moisture is found recycle the refrigerant.
A Restricted Orifice: There will be low suction
pressure and no cooling. This may be caused by
debris in the refrigerant system. If debris is believed
to be the cause, recycle the refrigerant and replace
the expansion valve and the receiver-drier.
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 -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Recover the refrigerant from the A/C system-
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the nut that secures the suction and
liquid line fittings to the stud on the expansion valve
(Fig. 6).
(4) Disconnect the suction and liquid lines from
the expansion valve.
(5) Remove the seals from the suction and liquid
line fitting and discard.
(6) Install plugs in, or tape over the opened liquid
and suction line fittings and both expansion valve
ports.
(7) Remove the two bolts that secure the expan-
sion valve to the evaporator tube tapping plate.
(8) Remove the expansion valve from the evapora-
tor tube tapping plate.(9) Remove the seals from the evaporator inlet and
outlet tube fittings and discard.
(10) Install plugs in, or tape over the opened evap-
orator inlet and outlet tube fittings and both expan-
sion valve ports.
INSTALLATION
(1) Remove the tape or plugs from the tapping
plate evaporator inlet and outlet tube fittings and
both ports on the back of the expansion valve.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the tapping plate
evaporator inlet and outlet tube fittings.
(3) Position the expansion valve onto the tapping
plate evaporator inlet and outlet tube fittings.
(4) Install and tighten the two bolts that secure
the expansion valve to the evaporator tube tapping
plate. Tighten the bolts to 5 N´m (45 in. lbs.).
(5) Remove the tape or plugs from the liquid and
suction line fittings and both expansion valve ports.
(6) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the liquid and suc-
tion line fittings.
(7) Reconnect the liquid line fitting to the expan-
sion valve.
(8) Reconnect the suction line fitting to the expan-
sion valve.
Fig. 6 Expansion Valve
1 - EVAPORATOR TUBE TAPPING PLATE
2 - O-RING SEAL (2)
3 - EXPANSION VALVE
4 - BOLT (2)
5 - SUCTION LINE
6 - NUT
7 - LIQUID LINE
8 - O-RING SEAL (2)
24 - 56 PLUMBINGVA
A/C EXPANSION VALVE (Continued)