2006 MERCEDES-BENZ SPRINTER heating

Two O-rings on the male half of the fitting are
used to seal the connection. These O-rings are com-
patible with R-134a refrigerant and must be replaced
with O-rings made of the same material.
Secondary clips are installed over the two con-
nected coupler halves at the factory for added blowoff
protection. In addition, some models have a plastic
ring that is used at the factory as a visual indicator
to confirm that these couplers are connected. After
the coupler is connected, the plastic indicator ring is
no longer needed; however, it will remain on the
refrigerant line near the coupler cage.
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 refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(2) Remove the secondary retaining clip from the
spring-lock coupler.
(3) Fit the proper size A/C line disconnect tool
(Special Tool Kit 7193) over the spring-lock coupler
cage (Fig. 38).(4) Close the two halves of the A/C line disconnect
tool around the spring-lock coupler.
(5) Push the A/C line disconnect tool into the open
side of the coupler cage to expand the garter spring.
Once the garter spring is expanded and while still
pushing the disconnect tool into the open side of the
coupler cage, pull on the refrigerant line attached to
the female half of the coupler fitting until the flange
on the female fitting is separated from the garter
spring and cage on the male fitting within the dis-
connect tool.
NOTE: The garter spring may not release if the A/C
line disconnect tool is cocked while pushing it into
the coupler cage opening.
(6) Open and remove the A/C line disconnect tool
from the disconnected spring-lock coupler.
(7) Complete the separation of the two halves of
the coupler fitting.
INSTALLATION
(1) Check to ensure that the garter spring is
located within the cage of the male coupler fitting,
and that the garter spring is not damaged.
(a) If the garter spring is missing, install a new
spring by pushing it into the coupler cage opening.
(b) If the garter spring is damaged, remove it
from the coupler cage with a small wire hook (DO
NOT use a screwdriver) and install a new garter
spring.
(2) Clean any dirt or foreign material from both
halves of the coupler fitting.
(3) Install new O-rings on the male half of the cou-
pler fitting.
Fig. 37 Spring-Lock Coupler - Typical
1 - MALE HALF SPRING-LOCK COUPLER
2 - FEMALE HALF SPRING-LOCK COUPLER
3 - SECONDARY CLIP
4 - CONNECTION INDICATOR RING
5 - COUPLER CAGE
6 - GARTER SPRING
7 - COUPLER CAGE
8 - O-RING SEALS
Fig. 38 Refrigerant Line Spring-Lock Coupler
Disconnect
VAPLUMBING 24 - 99

CAUTION: Use only the specified O-rings as they
are made of a special material for the R-134a sys-
tem. The use of any other O-rings may allow the
connection to leak intermittently during vehicle
operation.
(4) Lubricate the male fitting and O-rings, and the
inside of the female fitting with clean R-134a refrig-
erant oil. Use only refrigerant oil of the type recom-
mended for the compressor in the vehicle.
(5) Fit the female half of the coupler fitting over
the male half of the fitting.
(6) Push together firmly on the two halves of the
coupler fitting until the garter spring in the cage on
the male half of the fitting snaps over the flanged
end on the female half of the fitting.
(7) Ensure that the spring-lock coupler is fully
engaged by trying to separate the two coupler halves.
This is done by pulling the refrigerant lines on either
side of the coupler away from each other.
(8) Reinstall the secondary retaining clip over the
spring-lock coupler cage.
(9) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(10) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
UNDERBODY LINES
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.
NOTE: The underbody refrigerant lines for the
optional rear A/C system are serviced in five sec-
tions. Two sections are connected the A/C compres-
sor. Two sections of the underbody suction line
(low-side) are connected together by a tapping
block with an O-ring seal. The underbody A/C dis-
charge line uses a spring-lock type refrigerant line
coupler with an O-ring seal.
DISCHARGE LINE
(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) Using the proper A/C line disconnect tool, dis-
connect the underbody discharge line spring-lock cou-
pler from the compressor section of the underbody
discharge line and remove and discard the O-ring
seal (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING/REFRIGERANT LINE COUPLER -
REMOVAL) (Fig. 39).
(5) Disconnect the underbody discharge line from
the rear A/C discharge line and remove and discard
the O-ring seal.
(6) Install plug in, or tape over all of the opened
discharge line fittings.
(7) Disengage the fuel lines from the retaining clip
located near the transmission and position the fuel
lines out of the way.
(8) Remove the screws and brackets that secure
the discharge line to the underneath of the vehicle.
(9) Support transmission with a suitable lifting
device and remove the rear transmission crossmem-
ber (Refer to 13 - FRAME & BUMPERS/FRAME/
REAR CROSSMEMBER-TRANSMISSION -
REMOVAL).
(10) Remove the underbody discharge line from
the vehicle. Push the discharge line forward and over
the transmission, then pull it rearward to remove.
(11) If necessary, remove the bolt that secures the
compressor section of the underbody discharge line to
the A/C compressor and remove and discard the
O-ring seal. Make sure to plug in, or tape over the
opened discharge line fitting and compressor port.
24 - 100 PLUMBINGVA

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 CROSSMEMBER5 - SCREW AND BRACKET (2)
6 - DISCHARGE LINE-COMPRESSOR SECTION
7 - RETAINING CLIP
VAPLUMBING 24 - 101

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
24 - 102 PLUMBINGVA

(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).
VAPLUMBING 24 - 103

(3) Remove the clamp at the flexible pipe connec-
tion and the supplemental heater housing (if
required).
(4) Remove the three screws holding the exhaust
pipe to the body.
(5) Remove the steel exhaust pipe from the vehi-
cle.
(6) Remove the flexible exhaust pipe from the
vehicle (if required).
INSTALLATION
(1) Install the flexible exhaust pipe to the heater
unit. Tighten mounting clamp securely.
(2) Position the steel exhaust pipe to the flexible
exhaust and install and tighten the mounting clamp
securely.
(3) Install the three exhaust pipe screws, adjust
pipe placement as needed and tighten the screws
securely.
(4) Install the clamp to connect the steel exhaust
pipe to the flexible exhaust pipe and tighten clamp
securely.
(5) Check exhaust pipe exhaust end placement and
make any final adjustments.
(6) Lower the vehicle.
FUEL DOSING PUMP
DESCRIPTION
The dosing pump is a combined delivery, dosing
and shut-off system for the fuel supply to the supple-
mental cabin heater from the vehicle fuel tank.
OPERATION
The dosing pump is an electrically operated pump
that receives its operation instructions from the sup-
plemental cabin heater control module. The pump
supplies diesel fuel from the vehicle fuel tank to the
cabin heater.
REMOVAL
NOTE: The dosing pump is serviceable without
removing the component from the vehicle.
(1) Disconnect the rubber hose at the fuel line to
heater fuel pump. Leave the rubber hose on the fuel
line (Refer to 24 - HEATING & AIR CONDITION-
ING/CABIN HEATER/FUEL LINE - REMOVAL)
(Fig. 2).
(2) Disconnect the fuel line between the dosing
pump and the cabin heater unit.
Fig. 1 Cabin Heater Exhaust System
1 - MOUNTING SCREW (3)
2 - STEEL HEATER EXHAUST PIPE
3 - EXHAUST CLAMP (2)4 - FLEXIBLE HEATER EXHAUST PIPE
5 - HEATER SHIELD
6 - EXHAUST PIPE MOUNTING CLIP (3)
24 - 106 CABIN HEATERVA

NOTE: Position and retain the heater fuel line to
prevent fuel leakage while servicing the dosing
pump.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(3) Disconnect the wiring harness connector to the
fuel pump by depressing the integral spring and pull-
ing the connector away from the pump.
(4) Remove the dosing pump from the rubber iso-
lator.
INSTALLATION
(1) Install the dosing pump onto the rubber isola-
tor.
(2) Connect the fuel lines to the dosing pump and
the cabin heater unit.
NOTE: The connectors should point towards the
cabin heater fuel line.
(3) Use aviation style clamps to attach the hose to
the fuel pump nipples (Refer to 24 - HEATING &
AIR CONDITIONING/CABIN HEATER/FUEL LINE
- INSTALLATION).
(4) Connect the wire harness connector to the fuel
pump by depressing the integral spring and pushingthe connector towards the dosing pump. Pull the con-
nector towards the cabin heater to verify the instal-
lation.
(5) Verify function of the supplemental cabin
heater.
FUEL LINE
STANDARD PROCEDURE
CLEANING
(1) Remove the cabin heater fuel line (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - REMOVAL).
(2) With the cabin heater fuel line removed from
the vehicle, place a shop cloth on the fuel tank end of
the fuel line to catch any residue, then apply a small
amount of air pressure to the other end of the fuel
line.
(3) Check to see if air pressure is coming from the
tank end of the line. If pressure is flowing unre-
stricted the line is clean.
(4) If the fuel line shows any signs of being
restricted after air pressure is applied, the fuel line
should be replaced.
Fig. 2 Cabin Heater Dosing Pump Fuel Line
1 - FUEL LINE
2 - RETAINING CLAMP3 - DOSING PUMP
4 - HEATER AIR INTAKE PIPE
VACABIN HEATER 24 - 107

(5) Install the cabin heater fuel line (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - INSTALLATION).
(6) Verify function of the cabin heater.
REMOVAL
(1) Raise and support the vehicle. Take note of the
location of the flexible section of the cabin heater
exhaust tube.
NOTE: Have an approved fuel holding device ready
to capture any diesel fuel that drains from the fuel
line or cabin heater unit.
(2) Remove clamps on dosing pump end of fuel line
and separate line from the pump (Fig. 3).
24 - 108 CABIN HEATERVA