coolant MERCEDES-BENZ SPRINTER 2006 Service Manual

CAUSES OF BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
1. Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
2. A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged oil cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
3. Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
FLUID CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The torque converter should be replaced whenever
a failure generates sludge and debris. This is neces-
sary because normal converter flushing procedures
will not remove all contaminants.
STANDARD PROCEDURE
CHECK OIL LEVEL
(1) Verify that the vehicle is parked on a level sur-
face.
(2) Remove locking pin (1) (Fig. 149). Remove the
plate of the locking pin with a suitable tool and press
out the pin remaining in the cap downwards.
(3) Remove cap (2).
WARNING: Risk of accident from vehicle starting off
by itself when engine running. Risk of injury from
contusions and burns if you insert your hands into
the engine when it is started or when it is running.
Secure vehicle to prevent it from moving off by
itself. Wear properly fastened and close-fitting work
clothes. Do not touch hot or rotating parts.
(4) Actuate the service brake. Start engine and let
it run at idle speed in selector lever position ªPº.
(5) Shift through the transmission modes several
times with the vehicle stationary and the engine
idling
(6) Warm up the transmission, wait at least 2 min-
utes and check the oil level with the engine running.
Push the Oil Dipstick 8863A in up to the stop on the
electrohydraulic unit and pull out again, read off oil
level, repeat if necessary.
NOTE: The dipstick will protrude from the fill tube
approximately 75mm (3 inches) when installed.
Fig. 149 Remove Dipstick Tube Cap Lock
1 - LOCKING PIN
2 - TUBE CAP
3 - DIPSTICK TUBE
21 - 132 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

²Transmission fluid temperature
²Engine coolant temperature
²Input speed
²Throttle angle
²Engine speed
OPERATION
The converter impeller (driving member) (2) (Fig.
248), which is integral to the converter housing and
bolted to the engine drive plate, rotates at engine
speed. The converter turbine (driven member) (1),
which reacts from fluid pressure generated by the
impeller, rotates and turns the transmission input
shaft (4).
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft. (Fig. 249)
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over-run-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.0:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
Fig. 248 Torque Converter
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - TURBINE DAMPER
Fig. 249 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
21 - 182 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING
A/C PERFORMANCE....................3
HEATER PERFORMANCE TEST...........5
ATC FUNCTION TEST...................6
SPECIFICATIONS
HEATING-A/C SYSTEM..................6CONTROLS-FRONT........................8
CONTROLS - REAR......................24
DISTRIBUTION - FRONT...................45
DISTRIBUTION - REAR....................52
PLUMBING.............................60
CABIN HEATER.........................104
HEATING & AIR CONDITION-
ING
DESCRIPTION
An automatic temperature control (ATC) single
zone type heating-A/C system is standard equipment
on this model.
To maintain the performance level of the heating,
ventilation and air conditioning (HVAC) system, the
engine cooling system must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or A/C condenser
will reduce the performance of the A/C and engine
cooling systems.
The engine cooling system includes the radiator,
thermostat, radiator hoses and the engine coolant
pump. Refer to 7 - Cooling for more information
before opening or attempting any service to the
engine cooling system.
All vehicles are equipped with a common ventila-
tion housing (Fig. 1) located in the engine compart-
ment which includes:
²Blower motor
²Blower motor resistor block
²Recirculation door and actuator
All vehicles are also equipped with a common
heater housing (Fig. 2) mounted under the instru-
ment panel which includes:
²Heater core
²Evaporator core
²Evaporator temperature sensor
²Expansion valve
²Air outlet temperature sensor
²Mode doors
Fig. 1 Ventilation Housing
1 - NUT (5)
2 - WASHER (5)
3 - VENTILATION HOUSING
4 - HOUSING COVER
VAHEATING & AIR CONDITIONING 24 - 1

Some vehicles are equipped with an additional
Denso 10S17 A/C compressor mounted to the engine
which is used for the optional rear A/C system and
various add-on A/C systems (Fig. 3).A heater booster is used to aid in warming the
engine coolant. The heater booster system can be
switched on while the vehicle is being driven to help
the engine reach its normal operating temperature
quickly and will help aid in heating up the air within
the passenger compartment quickly when requested
by the operator (Fig. 4).
OPERATION
Outside air enters the vehicle through the hood
opening at the base of the windshield, and passes
through the ventilation housing located in the engine
compartment into the heater housing located behind
the instrument panel. Air flow velocity is adjusted
with the blower motor speed selector thumbwheel on
the A/C-heater control. The air intake openings must
be kept free of snow, ice, leaves, and other obstruc-
tions for the HVAC system to receive a sufficient vol-
ume of outside air.
The automatic temperature control (ATC) system
controls interior temperature by taking actual values
from the temperature sensors and the CAN bus and
comparing them to the nominal value of the temper-
ature control switch. The electric pulsed heater valve
is then energized depending on the requested quan-
tity of heat and an electrically-operated water pump
gives a nearly constant water flow for exact temper-
ature regulation. If the solenoid is not energized, the
coolant circuit to the heat exchanger is fully open. To
control the temperature the solenoid valve is pulsed
by the ATC in periods of four seconds.
The mode control knob on the A/C-heater control is
used to direct the conditioned air flow to the selected
air outlets. The mode control knob operates the mode
doors by cables connected to the mode doors.
Fig. 2 Heater 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)
Fig. 3 Denso 10S17 A/C Compressor
Fig. 4 Heater Booster
24 - 2 HEATING & AIR CONDITIONINGVA

When the outside air contains smoke, odors, high
humidity, or if rapid cooling is desired, interior air
can by recirculated by selecting the Recirculation
Mode with the mode control knob. The mode control
knob operates the recirculation door through use of a
vacuum actuator. When the Recirculation Mode is
selected, the recirculation door is closed to prevent
outside air from entering the passenger compart-
ment.
To maintain minimum evaporator temperature and
prevent evaporator freezing, an evaporator tempera-
ture sensor is used.
The A/C system is designed for the use of non-CFC,
R-134a refrigerant only and uses an expansion valve
to meter refrigerant flow to the evaporator.
DIAGNOSIS AND TESTING
A / C PERFORMANCE
The A/C system is designed to provide the passen-
ger compartment with low temperature and low
humidity air. The A/C evaporator, located in the
HVAC housing is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins of the A/C evaporator, the air transfers its heat
to the refrigerant in the evaporator coils and the
moisture in the air condenses on the evaporator fins.
During periods of high heat and humidity, an A/C
system will be more effective in the Recirculation
mode (max-A/C). With the system in the Recircula-
tion mode, only air from the passenger compartment
passes through the A/C evaporator. As the passenger
compartment air dehumidifies, the A/C system per-
formance levels rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and coils. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause oftrouble with the A/C system. The ambient air tem-
perature in the location where the vehicle will be
tested must be a minimum of 21É C (70É F) for this
test.
A / C PERFORMANCE TEST
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: Very specific instructions and conditions
pertain to this procedure which are significantly dif-
ferent than procedures used in other vehicle appli-
cations. Follow each step in the order they are
presented. Do not skip steps or change conditions
from those stated or results will be adversely
affected and invalid.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Check for diagnostic trouble codes using a
DRBIIItscan tool. If no DTCs are found in the
engine control module (ECM), go to Step 2. If any
DTCs are found, repair as required, then proceed to
Step 2.
(2) Place the vehicle in the shade and operate the
heating-A/C system under the following conditions.
²Engine at idle at operating temperature
²All doors or windows open
²Transaxle in Neutral
²All A/C duct louvers open
²A/C-heater controls set to fresh air (NOT Recir-
culate), full cool, panel mode, high blower and with
A/C compressor engaged.
NOTE: The A/C compressor clutch is de-energized
under any of the following conditions:
²Restricted compressor (thermal fuse in the pul-
ley)
²Low pressure in the system
²Low evaporator temperature
²Hard acceleration (WOT)
²High coolant temperatures
(3) Insert a thermometer in the driver side center
panel air outlet and operate the A/C system until the
thermometer temperature stabilizes.
VAHEATING & AIR CONDITIONING 24 - 3

Condition Possible Causes Correction
The low side pressure is
normal or slightly low, and
the high side pressure is too
low.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this
group. Test the refrigerant system for leaks.
Repair, evacuate and charge the refrigerant
system, if required.
2. Refrigerant flow through the
A/C evaporator is restricted.2. See A/C Evaporator in this group. Replace
the restricted A/C evaporator, if required.
3. Faulty A/C compressor. 3. See A/C Compressor in this group. Re-
place the A/C compressor, if required.
The low side pressure is
normal or slightly high, and
the high side pressure is too
high.1. A/C condenser air flow re-
stricted.1. Check the A/C condenser for damaged
fins, foreign objects obstructing air flow
through the condenser fins, and missing or
improperly installed air seals. Clean, repair, or
replace components as required.
2. Refrigerant flow through the
receiver/drier is restricted.2. See Receiver/Drier in this group. Replace
the restricted receiver/drier, if required.
3. Inoperative radiator cooling
fan.3. Test the radiator cooling fan and replace, if
required. Refer to Group 7 - Cooling.
4. Refrigerant system over-
charged.4. See Refrigerant System Charge in this
group. Recover the refrigerant from the refrig-
erant system. Charge the refrigerant system
to the proper level, if required.
5. Air in the refrigerant system. 5. See Refrigerant System Leaks in this
group. Test the refrigerant system for leaks.
Repair, evacuate and charge the refrigerant
system, if required.
6. Engine overheating. 6. Test the engine cooling system and repair,
if required. Refer to Group 7 - Cooling.
The low side pressure is too
high, and the high side pres-
sure is too low.1. Accessory drive belt slip-
ping.1. Inspect the accessory drive belt condition
and tension. Repair as required. Refer to
Group 7 - Cooling.
2. Faulty A/C expansion valve. 2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Faulty A/C compressor. 3. See A/C Compressor in this group. Re-
place the A/C compressor, if required.
The low side pressure is too
low, and the high side pres-
sure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid Line, Suction Line and Dis-
charge Line in this group. Inspect the refriger-
ant lines for kinks, tight bends or improper
routing. Correct the routing or replace the re-
frigerant line, if required.
2. Restricted refrigerant flow
through the A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Restricted refrigerant flow
through the A/C condenser.3. See A/C Condenser in this group. Replace
the restricted A/C condenser, if required.
HEATER PERFORMANCE TEST
Before performing the following tests, perform the
ATC Function Test using the DRBIIItand refer to
Cooling for the procedures to check the radiator cool-
ant level, serpentine drive belt tension, radiator air
flow and the radiator fan operation.
MAXIMUM HEATER OUTPUT
Engine coolant is provided to the heater core
through a heater valve and heater hose. With the
engine idling at normal operating temperature, set
the heater-A/C controls as follows:
²Temperature control in the full hot position
VAHEATING & AIR CONDITIONING 24 - 5

²Mode control in the floor heat position
²Blower motor control in the highest speed posi-
tion
Using a test thermometer, check the temperature
of the air being discharged at the floor outlets. Com-pare the test thermometer reading to the Tempera-
ture Reference chart.
TEMPERATURE REFERENCE CHART
Ambient Temperature Minimum Floor Outlet Temperature
Celsius Fahreheit Celsius Fahreheit
15.5É 60É 62.2É 144É
21.1É 70É 63.8É 147É
26.6É 80É 65.5É 150É
32.2É 90É 67.2É 153É
If the floor outlet air temperature is insufficient,
check for a faulty heater valve (perform ATC Func-
tion Test) and verify that the cooling system is oper-
ating to specifications (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS AND TESTING).
Both of the heater hoses should be HOT to the touch
(the coolant return heater hose should be slightly
cooler than the supply hose. If the coolant return
hose is much cooler than the supply hose, locate and
repair the engine coolant flow obstruction in the
heater system.
POSSIBLE LOCATIONS OR CAUSE OF
OBSTRUCTED COOLANT FLOW
²Pinched or kinked heater hoses.
²Improper heater hose routing.
²Plugged heater hoses or supply and return ports
at the cooling system connections.
²Inoperative or stuck heater water valve.
²Plugged heater core.
If proper coolant flow is verified, and heater floor
outlet air temperature is insufficient, a mechanical
problem may exist.
POSSIBLE LOCATIONS OR CAUSE OF INSUFFI-
CIENT HEAT
²An obstructed cowl air intake.
²Obstructed heater system outlets.
²Heater water valve not functioning properly.
TEMPERATURE CONTROL
If outlet air temperature cannot be adjusted with
the A/C-heater temperature control, one of the follow-
ing could require service:
²Faulty A/C-heater control switch.
²Faulty temperature sensor.²Faulty A/C-heater control cable or actuator.
²Faulty A/C-heater control module.
ATC FUNCTION TEST
The automatic temperature control (ATC) system
can perform an self-test, which can be activated by
the DRBIIItscan tool to confirm that the A/C system
is performing satisfactorily. This test provides a
quick confirmation of heating and A/C system perfor-
mance to the service technician. Refer to Body Diag-
nostic Procedures for the appropriate diagnostic
information.
SPECIFICATIONS
HEATING-A/CSYSTEM
FRONT A/C SYSTEM
Item Description Notes
A/C Compres-
sorDenso 7SBU16C ND-8 PAG oil
Freeze-up Con-
trolEvaporator tem-
perature sensorHVAC hous-
ing mounted -
input to A/C-
heater control
- operating
range of -10É
C (14É F) to
40É C (104É
F)
24 - 6 HEATING & AIR CONDITIONINGVA

OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley.
The compressor clutch engagement is controlled by
several components:
²A/C switch on the A/C-heater control panel
²Evaporator temperature sensor
²A/C pressure transducer
²Air temperature sensor
²CAN bus messages
The compressor clutch is de-energized under any of
the following conditions:
²Blocked compressor (thermal fuse in the pulley)
²Low pressure in the system
²Low evaporator temperature
²Hard acceleration (WOT)
²High coolant temperatures
STANDARD PROCEDURE
A / C COMPRESSOR CLUTCH AIR GAP
If a new clutch plate and/or clutch pulley are being
used, the air gap between the clutch plate and clutch
pulley must be checked using the following proce-
dure:
(1) Using feeler gauges, measure the air gap
between the clutch plate and the clutch pulley fric-
tion surfaces.
(2) If the air gap is not between specifications
(Refer to 24 - HEATING & AIR CONDITIONING -
SPECIFICATIONS), add or subtract shims until the
desired air gap is obtained.
NOTE: The shims may compress after tightening
the compressor shaft bolt. Check the air gap in four
or more places on the clutch plate to verify that the
air gap is still correct. Spin the clutch pulley before
making the final air gap check.
A / C COMPRESSOR CLUTCH BREAK - IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the heater-A/C control in the
Recirculation Mode, the A/C button in the on posi-
tion, the blower motor switch in the highest speed
position, and the engine speed at 1500 to 2000 rpm.
This procedure (burnishing) will seat the opposing
friction surfaces and provide a higher compressor
clutch torque capability.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, pulley, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Disconnect the engine wire harness connector
for the compressor clutch coil from the clutch coil
wire harness connector on the top of the compressor.
(4) Remove the retainer securing the compressor
clutch coil lead on the top of the compressor.
(5) Remove the bolt that secures the compressor
clutch to the compressor shaft (Fig. 2). If necessary, a
band-type oil filter wrench or strap wrench can be
placed around the clutch plate to aid in bolt
removal.
Fig. 1 A/C Compressor Clutch
1 - BOLT
2 - CLUTCH PLATE
3 - PULLEY AND BEARING
4 - FIELD COIL
5 - SNAP RING
6 - SNAP RING
7 - SHIM (2)
VACONTROLS-FRONT 24 - 9

(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