Mercedes-Benz Sprinter / Dodge Sprinter. Manual — part 518
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.
(1) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
A/C evaporator (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/HVAC
HOUSING
-
DISASSEMBLY).
(3) Lift the A/C evaporator out of the lower half of
the HVAC housing (Fig. 9).
INSTALLATION
NOTE: If the A/C evaporator is being replaced, add
60 milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.
(1) Install the A/C evaporator into the lower half of
the HVAC housing.
(2) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
A / C EXPANSION VALVE
DESCRIPTION
The A/C expansion valve controls the amount of
refrigerant entering the A/C evaporator and is of a
thermostatic expansion valve (TXV) design (Fig. 10).
The A/C expansion valve consists of an aluminum
H-valve type body with an integral thermal sensor.
The A/C expansion valve is located at the dash
panel between the A/C refrigerant lines and the A/C
evaporator.
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 A/C evaporator. A thermal sensor in the
A/C expansion valve monitors the temperature of the
refrigerant leaving the A/C evaporator and adjusts
the orifice size at the evaporator inlet to allow the
proper amount of refrigerant into the A/C evaporator
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)
Fig. 10 Front A/C Expansion Valve
1 - A/C EXPANSION VALVE
2 - THERMAL SENSOR
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24 - 73
in order to meet vehicle cooling requirements. Con-
trolling the refrigerant flow through the A/C evapo-
rator ensures that none of the refrigerant leaving the
evaporator is still in a liquid state, which could cause
damage to the A/C compressor.
The A/C expansion valve is factory calibrated and
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.
DIAGNOSIS AND TESTING
A / C EXPANSION VALVE
The A/C expansion valve is located on the engine
side of the dash panel near the shock tower.
The A/C expansion valve can fail in three different
positions (open, closed or restricted).
In an Open Position: this will result in a noisy A/C
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 A/C expansion valve. If excessive mois-
ture is found in the A/C system, recycle the refriger-
ant.
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 A/C expansion
valve is found to be defective replace the A/C expan-
sion 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 A/C expansion valve and the receiver-drier.
REMOVAL
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.
(1) Recover the refrigerant from the A/C system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Remove the nut that secures the suction and
liquid line fittings to the stud on the A/C expansion
valve (Fig. 11).
(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 A/C 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 A/C expansion valve onto the tap-
ping plate evaporator inlet and outlet tube fittings.
Fig. 11 A/C Expansion Valve
1 - EVAPORATOR TUBE TAPPING PLATE
2 - O-RING SEAL (2)
3 - A/C EXPANSION VALVE
4 - BOLT (2)
5 - A/C SUCTION LINE
6 - NUT
7 - A/C LIQUID LINE
8 - O-RING SEAL (2)
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PLUMBING
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(4) Install the two bolts that secure the A/C expan-
sion 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) Connect the liquid line fitting to the A/C expan-
sion valve.
(8) Connect the suction line fitting to the A/C
expansion valve.
(9) Install the nut that secures the suction line
and liquid line fittings to the stud on the A/C expan-
sion valve. Tighten the nut to 10 N·m (89 in. lbs.).
(10) Reconnect the negative battery cable.
(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).
ELECTRIC COOLANT PUMP
DESCRIPTION
The electric coolant pump ensures the uniform flow
of coolant through the heater core without bubbles,
even at low speeds (Fig. 12). The electric coolant
pump is located in the left side of the engine com-
partment near the battery and is controlled by the
A/C-heater control.
The electric coolant pump housing contains two
coolant hose connections and an electric motor which
drives
the
vane-type
pump
using
a
magnetic
clutch.
OPERATION
The electric coolant pump is controlled by the ATC
A/C-heater control and is only operational when the
ignition switch is on under the following conditions:
(1) Vehicle speed below 27 Km/h (17 mph).
(2) Coolant temperature above 65° C (150° F) but
less than 110° C (230 ° F).
(3) Any blower motor speed setting.
(4) Temperature heat setting above the halfway
setting (60% heat).
(5) The pump will turn off at speeds above 48
Km/h (30 mph).
(6) The pump will turn off if the coolant tempera-
ture rises above 110° C (230 ° F).
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Partially
drain
the
engine
cooling
system
(Refer to 7 - COOLING/ENGINE/COOLANT - STAN-
DARD PROCEDURE - DRAINING COOLANT SYS-
TEM).
(3) Disconnect the wire harness connector from the
electric coolant pump (Fig. 13).
(4) Loosen both hose clamps from the electric cool-
ant pump.
(5) Using a twisting motion gently remove both
heater hoses from the electric coolant pump.
(6) Remove the two electric coolant pump bracket
retaining nuts from the body studs.
(7) Remove the electric coolant pump from the
vehicle.
Fig. 12 Electric Coolant Pump
1 - ELECTRIC COOLANT PUMP
2 - COOLANT HOSE CONNECTIONS
3 - WIRE CONNECTOR
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24 - 75
INSTALLATION
(1) Install the electric coolant pump and mounting
bracket onto the body studs.
(2) Install the two bracket retaining nuts. Tighten
the nuts to 5 N·m (45 in. lbs.).
(3) Using a twisting motion gently install both
hoses onto the electric coolant pump.
(4) Tighten both hose clamps securely.
(5) Connect the wire harness connector to the elec-
tric coolant pump.
(6) Reconnect the negative battery cable.
(7) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE - COOLING SYSTEM FILL).
HEATER CORE
DESCRIPTION
The heater core is mounted into the HVAC hous-
ing, located behind the instrument panel (Fig. 14).
The heater core is a heat exchanger made of rows of
tubes and fins. The heater core tubes are attached to
the heater core by using O-ring seals and bolts.
The heater core is serviced by removing and disas-
sembling the HVAC housing.
OPERATION
Engine coolant is circulated through the heater
hoses to the heater core whenever the heater water
valve is cycled open by the ATC A/C-heater control.
As the coolant flows through the heater core, heat
removed from the engine is transferred to the heater
core fins and tubes. Air directed through the heater
core picks up the heat from the heater core fins. The
heater water valve controls the heater output air
temperature by controlling the amount of heated
engine coolant flowing through the heater core. The
blower motor speed controls the volume of air flowing
through the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
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.
Fig. 13 Electric Coolant Pump
1 - HEATER HOSE
2 - HOSE CLAMP (2)
3 - HEATER HOSE
4 - ELECTRIC COOLANT PUMP
5 - WIRE HARNESS CONNECTOR
6 - NUT (2)
Fig. 14 Front Heater Core
1 - HEATER CORE
2 - BOLT (3)
3 - HEATER CORE TUBES
4 - O-RING SEALS
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PLUMBING
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