engine MERCEDES-BENZ SPRINTER 2006 Service Manual

BLOWER MOTOR
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the engine air cleaner housing cover
(Refer to 9 - ENGINE/AIR INTAKE SYSTEM/AIR
CLEANER ELEMENT - REMOVAL).
(3) Position the ventilation housing insulation
blanket out of the way of the blower motor assembly.
(4) Disconnect the wire harness connector from the
blower motor (Fig. 4).
(5) Remove the three blower motor retaining
screws.
(6) Remove the blower motor assembly from the
ventilation housing.
INSTALLATION
(1) Install the blower motor assembly into the ven-
tilation housing.
(2) Install the three blower motor retaining
screws. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the wire harness connector to the
blower motor.
(4) Install the ventilation housing insulation blan-
ket.
(5) Install the engine air cleaner cover (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(6) Reconnect the negative battery cable.
DEFROSTER DUCTS
REMOVAL
(1) Remove the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL - REMOVAL).
(2) Remove the screw that secures the left and/or
right side defroster duct to the heater housing,
depending on the duct being removed (Fig. 5).
(3) Remove the defroster duct(s) from the hous-
ing.
INSTALLATION
(1) Install the left and/or right side defroster duct
on to the heater housing.
(2) Install the screw that secures the defroster
duct to the housing. Tighten the screw(s) to 2 N´m
(17 in. lbs.).
(3) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL - INSTALLATION).
FLOOR DISTRIBUTION DUCTS
REMOVAL
(1) Remove the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL).
(2) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(3) Remove the screws that secure the left and
right floor distribution ducts to the instrument panel
support (Fig. 6).
(4) Remove floor distribution ducts from the center
floor distribution duct.
Fig. 4 Blower Motor Assembly
1 - VENTILATION HOUSING
2 - SCREWS (3)
3 - WIRE HARNESS CONNECTOR
4 - BLOWER MOTOR
5 - INSULATION BLANKET
Fig. 5 Defroster Duct - RH Shown, LH Typical
1 - HEATER HOUSING
2 - SCREW
3 - DEFROSTER DUCT
VADISTRIBUTION - FRONT 24 - 47

(5) Remove the shift mechanism (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
NAG1/SHIFT MECHANISM - REMOVAL).
(6) Remove center floor distribution duct from the
heater housing.
INSTALLATION
(1) Install the center floor distribution duct onto
the heater housing.
(2) Install the shift mechanism (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
NAG1/SHIFT MECHANISM - INSTALLATION).
(3) Install the left and right floor distribution
ducts onto the center floor distribution duct.
(4) Install the left and right floor distribution duct
retaining screws to the instrument panel support.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Install the defroster ducts (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/DE-
FROSTER DUCTS - INSTALLATION).
(6) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
HVAC HOUSING
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The HVAC housing must be removed from
the vehicle and the two halves of the housing sep-
arated for service access of the heater core, A/C
evaporator and each of the various mode doors.
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY)
(2) Partially drain the engine cooling system
(Refer to 7 - COOLING/ENGINE/COOLANT - STAN-
DARD PROCEDURE - DRAINING COOLING SYS-
TEM).
(3) Disconnect and isolate the negative battery
cable.
(4) Remove the air cleaner housing (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(5) Remove the windshield washer reservoir (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - REMOVAL).
(6) Remove the air filter from the ventilation hous-
ing (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION/AIR FILTER - REMOVAL).
(7) Disconnect the wire harness and vacuum con-
nectors from the recirculation door actuator (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS/
RECIRCULATION DOOR ACTUATOR - REMOVAL).
(8) Disconnect the wire harness connector from the
blower motor resistor block (Refer to 24 - HEATING
& AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - REMOVAL).
(9) Disconnect the wire harness connector from the
blower motor (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/BLOWER MOTOR -
REMOVAL).
(10) Remove the nuts and washers that secure the
ventilation housing to the body and remove the ven-
tilation housing from the vehicle (Fig. 7).
Fig. 6 Floor Distribution Duct, RH Shown, LH
Typical
1 - HEATER HOUSING
2 - SCREW (1)
3 - RH FLOOR DUCT
4 - CENTER FLOOR DUCT
24 - 48 DISTRIBUTION - FRONTVA

(3) Remove the gasket located at the A/C evapora-
tor and heater core tubes and the gasket that seals
the ventilation housing to the HVAC housing (Fig. 9).
(4) Remove the 12 screws that secure the two
housing halves together.
(5) Seperate the two housing halves.
(6) Remove the heater core from the lower hous-
ing.
(7) Remove the wire harness.
(8) Remove the three heater core tube retaining
bolts and the heater core tube assembly from the
heater core.
(9) Remove the heater core tube seals and discard.
(10) Install plug in, or tape over the opened heater
core fittings.
(11) Remove the A/C evaporator from the lower
housing.
ASSEMBLY
(1) Install the A/C evaporator into the lower hous-
ing.
(2) Remove the tape or plugs from the heater core
fittings.(3) Lubricate two new rubber O-ring seals with
clean engine coolant and install them onto the heater
core fitting.
(4) Connect the heater core tube assembly to the
heater core and install the three retaining bolts.
Tighten the bolts to 5 N´m (45 in. lbs.).
(5) Install the wire harness.
(6) Install the heater core into the lower housing.
(7) Install the two housing halves together.
(8) Install the 12 screws that secure the two hous-
ing halves together. Tighten the screws to 2 N´m (17
in. lbs.).
(9) Install the gasket for the A/C evaporator and
heater core tube outlets and the gasket that seals the
ventilation housing to the HVAC housing.
(10) Install the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - INSTALLATION).
INSTALLATION
NOTE: High pressures are produced in the refriger-
ant system when the A/C compressor is operating.
Extreme care must be exercised to make sure that
each of the refrigerant system connections is pres-
sure-tight and leak free.
(1) Position the HVAC housing to the dash panel.
Be certain that the evaporator condensate drain tube
is positioned correctly.
(2) Install the screws that secure the HVAC hous-
ing to the dash panel. Tighten the screws to 4.5 N´m
(40 in. lbs.).
(3) Connect the HVAC housing wire harness con-
nectors and install the wiring harness to the bracket.
(4) Connect the A/C-heater control cables to the
mode door levers (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/MODE DOOR CABLE
- INSTALLATION).
(5) Reinstall the passenger airbag bracket (Refer
to 8 - ELECTRICAL/RESTRAINTS/PASSENGER
AIRBAG - INSTALLATION).
(6) Reconnect the two bulkhead ground connection
near the instrument cluster area.
(7) Reinstall the defroster, floor distribution and
instrument panel ducts.
(8) Reinstall the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(9) Unplug or remove the tape from the opened
refrigerant line fittings.
(10) Lubricate two new rubber O-ring seals with
clean refrigerant oil and install them onto the evap-
orator core fittings.
(11) Connect the refrigerant line terminal block to
the evaporator tubes.
Fig. 9 HVAC Housing
1 - SCREW (12)
2 - UPPER HOUSING
3 - A/C EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
5 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - LOWER 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)
24 - 50 DISTRIBUTION - FRONTVA

(12) Install the two bolts that secure the refriger-
ant line terminal block to the A/C evaporator.
Tighten the bolts to 5 N´m (45 in. lbs.).
(13) Unplug or remove the tape from the heater
core hoses and tubes.
(14) Connect the heater hoses to the heater core
tubes and install the heater hose clamps.
(15) Install the ventilation housing to the dash
panel.
(16) Install the nuts and washers that secure the
ventilation housing to the dash panel. Tighten the
nuts to 5 N´m (45 in. lbs.).
(17) Connect the wire harness connectors to the
blower motor, blower motor resistor block and the
recirculation door actuator.
(18) Connect the vacuum harness connector to the
recirculation door actuator.
(19) Install the air filter into the ventilation hous-
ing (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION/AIR FILTER -
INSTALLATION).
(20) Install the windshield washer reservoir (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - INSTALLATION).
(21) Install the air cleaner housing (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(22) Reconnect the negative battery cable.
(23) If the heater core is being replaced, flush the
cooling system (Refer to 7 - COOLING - STANDARD
PROCEDURE - COOLING SYSTEM CLEANING/
REVERSE FLUSHING).
(24) Refill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE - COOLANT SYSTEM FILL).
(25) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(26) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
INSTRUMENT PANEL DUCTS
REMOVAL
(1) Remove the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL).
(2) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(3) Remove the floor distribution ducts (Refer to 24
- HEATING & AIR CONDITIONING/DISTRIBU-
TION/FLOOR DISTRIBUTION DUCTS -
REMOVAL).(4) If removing the right instrument panel duct,
remove the passenger air bag module and bracket
(Refer to 8 - ELECTRICAL/RESTRAINTS/PASSEN-
GER AIRBAG - REMOVAL).
(5) Remove the screws that secure the left and/or
right instrument panel duct and remove the duct(s)
as required (Fig. 10).
INSTALLATION
(1) Connect the instrument panel duct(s) to the
heater housing as required.
(2) Install the instrument panel duct retaining
screws. Tighten the screws to 2 N´m (17 in. lbs.).
(3) If servicing the right instrument panel duct,
install the passenger air bag module and bracket
(Refer to 8 - ELECTRICAL/RESTRAINTS/PASSEN-
GER AIRBAG - INSTALLATION).
(4) Install the floor distribution ducts (Refer to 24
- HEATING & AIR CONDITIONING/DISTRIBU-
TION/FLOOR DISTRIBUTION DUCTS - INSTAL-
LATION).
(5) Install the defroster ducts (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/DE-
FROSTER DUCTS - INSTALLATION).
(6) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
Fig. 10 Instrument Panel Duct - RH Shown, LH
Typical
1 - RH DEFROSTER DUCT
2 - SCREW (2)
3 - RH INSTRUMENT PANEL DUCT
4 - RH FLOOR DISTRIBUTION DUCT
5 - CENTER FLOOR DISTRIBUTION DUCT
VADISTRIBUTION - FRONT 24 - 51

REAR REFRIGERANT RESERVOIR
REMOVAL.............................95
INSTALLATION.........................95
REAR SUCTION LINE
DESCRIPTION.........................96
REMOVAL.............................96
INSTALLATION.........................98
REFRIGERANT LINE COUPLER
DESCRIPTION.........................98OPERATION...........................98
REMOVAL.............................99
INSTALLATION.........................99
UNDERBODY LINES
REMOVAL............................100
INSTALLATION........................102
PLUMBING
DESCRIPTION
The refrigerant lines and hoses are used to carry
the refrigerant between the various air conditioning
system components. A barrier hose design with a
nylon tube, which is sandwiched between rubber lay-
ers, is used for the R-134a air conditioning system on
this vehicle. This nylon tube helps to further contain
the R-134a refrigerant, which has a smaller molecu-
lar structure than R-12 refrigerant. The ends of the
refrigerant hoses are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.
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.
OPERATION
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.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.
WARNINGS
WARNING: The A/C system contains refrigerant
under high pressure. Repairs should only be per-
formed by qualified service personnel. Severe per-
sonal injury or death may result from improper
service procedures.
WARNING: Avoid breathing the refrigerant and
refrigerant oil vapor or mist. Exposure may irritate
the eyes, nose, and/or throat. Wear eye protectionwhen servicing the A/C refrigerant system. Serious
eye injury can result from direct contact with the
refrigerant. If eye contact occurs, seek medical
attention immediately.
WARNING: Do not expose the refrigerant to open
flame. Poisonous gas is created when refrigerant is
burned. An electronic leak detector is recom-
mended. Severe personal injury or death may result
from improper service procedures.
WARNING: If accidental system discharge occurs,
ventilate the work area before resuming service.
Large amounts of refrigerant released in a closed
work area will displace the oxygen and cause suf-
focation and death.
WARNING: The evaporation rate of R-134a refriger-
ant at average temperature and altitude is extremely
high. As a result, anything that comes in contact
with the refrigerant will freeze. Always protect the
skin or delicate objects from direct contact with the
refrigerant.
WARNING: The R-134a service equipment or the
vehicle refrigerant system should not be pressure
tested or leak tested with compressed air. Some
mixtures of air and R-134a have been shown to be
combustible at elevated pressures. These mixtures
are potentially dangerous, and may result in fire or
explosion causing property damage, personal injury
or death.
WARNING: The engine cooling system is designed
to develop internal pressures of 97 to 123 kilopas-
cals (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.
Allow the vehicle to cool for a minimum of 15 min-
utes before opening the cooling system for service.
Failure to observe this warning can result in seri-
ous burns from the heated engine coolant.
VAPLUMBING 24 - 61

SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approximately 28 in Hg.)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE). Determine if the
system holds a vacuum for 15 minutes. If vacuum is
held, a leak is probably not present. If system will
not maintain vacuum level, proceed to Step 2.
(2) Prepare and dispense 0.284 kilograms (10
ounces) of R-134a refrigerant into the evacuated
refrigerant system (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE) and
proceed to Step 1 of the System Low procedure.
SYSTEM LOW
(1) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(2) Operate the heating-A/C system with the
engine at idle under the following conditions for at
least five minutes.
²Doors or windows open
²Transmission in Park
²A/C-heater controls set to outside air, full cool,
panel mode, high blower and with A/C compressor
engaged
CAUTION: A leak detector only designed for R-12
refrigerant will not detect leaks in a R-134a refriger-
ant system.
(3) Shut the vehicle Off and wait 2-7 minutes.
Then use an electronic leak detector that is designed
to detect R-134a refrigerant and search for leaks. Fit-
tings, lines or components that appear to be oily usu-
ally indicate a refrigerant leak. To inspect the A/C
evaporator for leaks, insert the leak detector probe
into the drain tube opening or an air outlet. A dye for
R-134a is available to aid in leak detection. Use only
DaimlerChrysler approved refrigerant dye.
STANDARD PROCEDURE
REFRIGERANT SYSTEM SERVICE EQUIPMENT
WARNING: Eye protection must be worn when ser-
vicing an A/C refrigerant system. Turn off (rotate
clockwise) all valves on the equipment being used,
before connecting to or disconnecting from the
refrigerant system. Failure to observe these warn-
ings may result in possible personal injury.
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Referto 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 must be used.
Contact an automotive service equipment supplier for
refrigerant recovery/recycling/charging equipment.
Refer to the operating instructions supplied by the
equipment manufacturer for proper care and use of
this equipment.
A manifold gauge set may be needed with some
recovery/recycling/charging equipment (Fig. 1). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
Fig. 1 Manifold Gauge Set - Typical
1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/ BLACK
STRIPE)
4 - HIGH PRESSURE HOSE (RED W/ BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/ BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE
VAPLUMBING 24 - 63

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
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.
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 Tempera-
ture16ÉC
(60ÉF)21ÉC
(70ÉF)27ÉC
(80ÉF)32ÉC
(90ÉF)38ÉC
(100ÉF)43ÉC
(110ÉF)
Compressor Dis-
charge Pressure1378 kPa
(200 psi)1516 kPa
(220 psi)1723 kPa
(250psi)1930 kPa
(280 psi)2206 kPa
(320 psi)2413 kPa
(350 psi)
VAPLUMBING 24 - 65

(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.
A / C COMPRESSOR
DESCRIPTION
The standard front A/C system uses a Denso
7SBU16C seven cylinder, variable displacement
swash plate-type A/C compressor (Fig. 2). This A/C
compressor has a volume control which is regulated
by an internal control valve and has both the suction
and discharge ports located at the rear of the com-
pressor.
The optional independant Konvekta rear A/C sys-
tem uses theDenso 10S17C ten cylinder, double-act-
ing swash plate-type A/C compressor (Fig. 3). This
A/C compressor has a fixed displacement of 170 cubic
centimeters (10.374 cubic inches), and has both the
suction and discharge ports located on the cylinder
head at the rear of the compressor.A label identifying the use of R-134a refrigerant is
located on both A/C compressors.
OPERATION
The A/C compressor is driven by the engine
through an electric clutch, drive pulley and belt
arrangement. The A/C compressor is lubricated by
refrigerant oil that is circulated throughout the
refrigerant system with the refrigerant.
The A/C compressor draws in low-pressure refrig-
erant vapor from the A/C evaporator through its suc-
tion port. It then compresses the refrigerant into a
high-pressure, high-temperature refrigerant vapor,
which is then pumped to the A/C condenser through
the compressor discharge port.
The A/C compressor cannot be repaired and, if
faulty or damaged, it must be replaced. The compres-
sor clutch, pulley and bearing assembly, and clutch
field coil are available for service. If an internal fail-
ure of the A/C compressor has occurred, the receiver/
drier must also be replaced.
DIAGNOSIS AND TESTING
A / C 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,
Fig. 2 Denso 7SBU16C A/C Compressor
1 - A/C COMPRESSOR (DENSO 7SBU16C)
2 - SUCTION AND DISCHARGE PORT
3 - INTERNAL CONTROL VALVE
Fig. 3 Denso 10S17C A/C Compressor
1 - A/C COMPRESSOR (DENSO 10S17C)
2 - SUCTION AND DISCHARGE PORT
3 - CYLINDER HEAD
24 - 66 PLUMBINGVA

mounting brackets, or a loose compressor clutch
assembly.
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
DENSO 7SBU16CA/CCOMPRESSOR
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The A/C compressor may be removed and
repositioned without disconnecting the refrigerant
lines or discharging the refrigerant system. Dis-
charging is not necessary if servicing the compres-
sor clutch, clutch coil or the engine.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(1) Disconnect and isolate the negative battery
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(3) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
(4) Disconnect the wire harness connector from the
A/C compressor clutch coil.
(5) Remove the bolts that secure the A/C suction
and discharge lines to the A/C compressor.
(6) Disconnect the A/C suction and discharge lines
from the A/C compressor and remove and discard the
O-ring seals (Fig. 4).
(7) Install plugs in, or tape over the opened refrig-
erant line fittings and the compressor ports.
(8) Raise the vehicle on a hoist.
(9) If equipped with an add-on rear A/C system,
remove the lower A/C compressor and position it out
of the way (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
REMOVAL - DENSO 10S17).
(10) Support the A/C compressor and remove the
compressor mounting bolts.
(11) Remove the A/C compressor from the engine
compartment.
VAPLUMBING 24 - 67

DENSO 10S17A/CCOMPRESSOR
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The A/C compressor may be removed and
repositioned without disconnecting the refrigerant
lines or discharging the refrigerant system. Dis-
charging is not necessary if servicing the compres-
sor clutch, clutch coil or the engine.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Raise and support the vehicle.(4) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
(5) Disconnect the wire harness connector from the
clutch field coil of the A/C compressor (Fig. 5).
(6) Remove the bolts that secure the underbody
suction and discharge lines to the A/C compressor.
(7) Disconnect the underbody suction and dis-
charge lines from the A/C compressor and remove
and discard the O-ring seals.
(8) Install plugs in, or tape over the opened refrig-
erant line fittings and the compressor ports.
(9) Remove the bolts that secure the A/C compres-
sor to the mounting bracket.
(10) Remove the A/C compressor from the engine
compartment.
INSTALLATION
DENSO 7SBU16CA/CCOMPRESSOR
NOTE: Be certain to check the refrigerant oil level if
the A/C compressor is being replaced. See Refriger-
ant Oil Level in this group for the procedures. Use
only refrigerant oil of the type recommended for the
A/C compressor in the vehicle.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(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.).
Fig. 4 Denso 7SBU16C A/C Compressor
1 - A/C COMPRESSOR
2 - O-RING SEAL
3 - A/C SUCTION LINE
4 - BOLT
5 - RETAINING CLIP
6 - BOLT
7 - A/C DISCHARGE LINE
8 - O-RING SEAL
Fig. 5 Denso 10S17 A/C Compressor
1 - REFRIGERANT LINES
2 - WIRE HARNESS CONNECTOR
3 - BOLTS (3)
4 - A/C COMPRESSOR
24 - 68 PLUMBINGVA