Mercedes-Benz Sprinter / Dodge Sprinter. Service manual — part 525

SUCTION LINE - FRONT SECTION

(1) Remove the cover from the rear A/C evaporator

housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - REMOVAL).

(2) Recover the refrigerant from the rear refriger-

ant system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).

(3) Raise and support the vehicle.
(4) Disconnect the connection of the front section

of the underbody suction line from the compressor
section of the underbody suction line and remove and
discard the O-ring seal (Fig. 40).

(5) Remove the bolt that secures the connection of

the front section of the underbody suction line to the
rear section of the underbody suction line.

(6) Disconnect the front section of the underbody

suction line from the rear section and remove and
discard the O-ring seal.

(7) Install plug in, or tape over all of the opened

suction line fittings.

(8) Remove the screws and brackets that secure

the front section of the underbody suction line to the
underneath of the vehicle and remove the front sec-
tion of the suction line.

(9) If necessary, remove the bolt that secures the

compressor section of the underbody suction line to
the A/C compressor and remove and discard the
O-ring seal. Make sure to plug in, or tape over the
opened underbody suction line fitting and compressor
port.

Fig. 39 Underbody Discharge Line

1 - UNDERBODY DISCHARGE LINE
2 - FUEL LINES
3 - REAR A/C DISCHARGE
4 - REAR TRANSMISSION CROSSMEMBER

5 - SCREW AND BRACKET (2)
6 - DISCHARGE LINE-COMPRESSOR SECTION
7 - RETAINING CLIP

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SUCTION LINE - REAR SECTION

(1) Remove the cover from the rear A/C evaporator

housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - REMOVAL).

(2) Recover the refrigerant from the rear refriger-

ant system (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).

(3) Raise and support the vehicle.
(4) Remove the bolt that secures the connection of

the front section of the underbody suction line to the
rear section of the underbody suction line (Fig. 41).

(5) Disconnect the front section of the underbody

suction line from the rear section and remove and
discard the O-ring seal.

(6) Disconnect the rear section of the underbody

suction line from the rear A/C suction line and
remove and discard the O-ring seal.

(7) Install plug in, or tape over all of the opened

suction line fittings.

(8) Remove the screws and brackets that secure

the rear section of the underbody suction line to the
underneath of the vehicle and remove the rear sec-
tion of the suction line.

INSTALLATION

DISCHARGE LINE

(1) If the compressor section of the underbody dis-

charge line was removed from the A/C compressor,
remove plugs or tape from the discharge line fitting,
lubricate a new rubber O-ring seal with clean refrig-
erant oil, install it onto the discharge line fitting and
install the bolt that secures the discharge line to the
compressor. Tighten the bolt to 21 N·m (15 ft. lbs.).

(2) Position the underbody discharge line to the

vehicle.

(3) Install the brackets and screws that secure the

underbody discharge line to the underneath of the
vehicle. Tighten the screws to 8 N·m (70 in. lbs.).

(4) Engage the fuel lines to the retaining clips

located near the transmission.

(5) Install

the

rear

transmission

crossmember

(Refer to 13 - FRAME & BUMPERS/FRAME/REAR
CROSSMEMBER-TRANSMISSION

-

INSTALLA-

TION).

(6) Remove the plugs or tape from the discharge

line fittings.

(7) Lubricate new rubber O-ring seals with clean

refrigerant oil and install them onto the discharge
line fittings.

(8) Connect the underbody discharge line spring-

lock coupler to the compressor section of the dis-
charge line and install the secondary retaining clip
(if equipped) (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/REFRIGERANT LINE COU-
PLER - INSTALLATION).

Fig. 40 Underbody Suction Line - Front Section

1 - UNDERBODY SUCTION LINE-FRONT SECTION
2 - BOLT
3 - UNDERBODY SUCTION LINE-REAR SECTION
4 - SUCTION LINE-COMPRESSOR SECTION
5 - SCREW AND BRACKET (2)

Fig. 41 Underbody Suction Line - Rear Section

1 - REAR A/C DISCHARGE LINE
2 - UNDERBODY SUCTION LINE-REAR SECTION
3 - SCREW AND BRACKET (3)
4 - BOLT
5 - UNDERBODY SUCTION LINE-FRONT SECTION

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(9) Connect the rear A/C discharge line to the

underbody discharge line. Tighten the nut to 35 N·m
(26 ft. lbs.).

(10) Lower the vehicle.
(11) Evacuate the rear refrigerant system (Refer to

24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).

(12) Charge the rear refrigerant system (Refer to

24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).

(13) Install the cover onto the rear A/C evaporator

housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).

SUCTION LINE - FRONT SECTION

(1) If the compressor section of the underbody suc-

tion line was removed from the A/C compressor,
remove plugs or tape from the suction line fitting,
lubricate a new rubber O-ring seal with clean refrig-
erant oil, install it onto the suction line fitting and
install the bolt that secures the suction line to the
compressor. Tighten the bolt to 21 N·m (15 ft. lbs.).

(2) Position the front section of the underbody suc-

tion line to the vehicle.

(3) Install the brackets and screws that secure the

front section of the underbody suction line to the
underneath of the vehicle. Tighten the screws to 8
N·m (70 in. lbs.).

(4) Remove the plugs or tape from the suction line

fittings.

(5) Lubricate new rubber O-ring seals with clean

refrigerant oil and install them onto the suction line
fittings.

(6) Connect the front section of the underbody suc-

tion line to the compressor section of the suction line.
Tighten the nut to 35 N·m (26 ft. lbs.).

(7) Connect the front section of the underbody suc-

tion line to the rear section of the suction line and
install the retaining bolt. Tighten the bolt to 25 N·m
(18 ft. lbs.).

(8) Lower the vehicle.
(9) Evacuate the rear refrigerant system (Refer to

24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).

(10) Charge the rear refrigerant system (Refer to

24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).

(11) Install the cover onto the rear A/C evaporator

housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).

SUCTION LINE - REAR SECTION

(1) Position the rear section of the underbody suc-

tion line to the vehicle.

(2) Install the brackets and screws that secure the

rear section of the underbody suction line to the
underneath of the vehicle. Tighten the screws to 8
N·m (70 in. lbs.).

(3) Remove the plugs or tape from the suction line

fittings.

(4) Lubricate new rubber O-ring seals with clean

refrigerant oil and install them onto the suction line
fittings.

(5) Connect the rear section of the underbody suc-

tion line to the front section of the suction line and
install the retaining bolt. Tighten the bolt to 25 N·m
(18 ft. lbs.).

(6) Connect the rear section of the underbody suc-

tion line to the rear A/C suction line. Tighten the nut
to 35 N·m (26 ft. lbs.).

(7) Lower the vehicle.
(8) Evacuate the rear refrigerant system (Refer to

24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).

(9) Charge the rear refrigerant system (Refer to 24

- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).

(10) Install the cover onto the rear A/C evaporator

housing (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/A/C EVAPORA-
TOR COVER-REAR - INSTALLATION).

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CABIN HEATER

TABLE OF CONTENTS

page

page

CABIN HEATER

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . 104

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . 104

DIAGNOSIS AND TESTING

SUPPLEMENTAL CABIN HEATER

. . . . . . . . 104

EXHAUST TUBE

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . 106

FUEL DOSING PUMP

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . 106

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . 106

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . 107

FUEL LINE

STANDARD PROCEDURE

CLEANING

. . . . . . . . . . . . . . . . . . . . . . . . . 107

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . 109

HEATER UNIT

REMOVAL

HEATER UNIT

. . . . . . . . . . . . . . . . . . . . . . . 110

WIRE HARNESS

. . . . . . . . . . . . . . . . . . . . . 110

INSTALLATION

HEATER UNIT

. . . . . . . . . . . . . . . . . . . . . . . 110

WIRE HARNESS

. . . . . . . . . . . . . . . . . . . . . 111

INLET HOSE

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . 112

CABIN HEATER

DESCRIPTION

Vehicles equipped with the diesel engine are also

equipped with a supplemental cabin heater. This
cabin heater is mounted under the vehicle and oper-
ates similar to an oil fired furnace. The heater burns
small amounts of fuel to provide additional heat to
the coolant. Coolant is routed from the engine, to the
supplemental cabin heater and then to the front
heater core. This provides additional heat to the pas-
senger compartment. The supplemental cabin heater
system is interfaced to the vehicles on-board com-
puter systems and DRBIII

t diagnostics.

The supplemental cabin heater has an electronic

control module that monitors the heat output of the
heater. The cabin heater operates at full load (5 kW),
half load or idle mode (no additional heat) depending
on engine coolant temperature.

OPERATION

The supplemental cabin heater is activated by

using the temperature control on the A/C-heater con-
trol. The supplemental cabin heater is activated
when the temperature control is set to/or above the
upper set point. The supplemental cabin heater can
operate in a full or partial load range as well as an
idle mode, all dependent on the engine coolant tem-
perature. The heater unit will also turn off if the
temperature control is set to less than the lower set
point. The supplemental cabin heater can take up to
three minutes to completely shut down when either

the heater temperature is set below the lower set
point or the vehicle ignition is turned off.

The supplemental cabin heater only operates when

the engine is running, the mileage exceeds 8 kilome-
ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The heater should start if the coolant temper-
ature is below 40° C (104° F).

NOTE: Do not apply a strong vacuum directly on
the supplemental cabin heater exhaust line. Place
the vacuum within 75 mm (3 inches) of the exhaust
port. Too strong of a vacuum can prevent the heater
from starting. The heater control module monitors
the blower speed and combustion during its start-
up.

DIAGNOSIS AND TESTING

SUPPLEMENTAL CABIN HEATER

Refer to the Symptoms Diagnosis table for basic

checks of the diesel fueled supplemental cabin heater.

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CABIN HEATER

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