2005 MERCEDES-BENZ SPRINTER radiator

²Higher torque as a result of improved cylinder
charge.
²Reduction in exhaust emissions as a result of an
improvement in the air supply of the engine.
²Increased power output as a result of the higher
charge pressure combined with a reduced exhaust
backpressure and thus improved charge cycle.
OPERATION
The exhaust gases of the engine are directed
through the exhaust manifold into the turbine hous-
ing onto the turbine wheel (Fig. 2). The flow energy
of the exhaust gases cause the turbine wheel to
rotate. Consequently, the compressor wheel, which is
connected through the turbine shaft with the turbine
wheel, is driven at the same speed. The fresh air
inducted by the compressor wheel is compressed and
passed to the engine (Fig. 2).
The charge pressure is controlled by varying the
position of the guide vanes (Fig. 2). The guide stud of
the control linkage of the boost pressure actuator
turns the adjusting ring in the turbine housing (Fig.
2). As a result, all the guide vanes whose guide studs
likewise mesh into the adjusting ring, are also
turned (Fig. 2).
At low speeds, the flow cross-section is reduced by
closing the guide vanes (Fig. 2). Consequently the
speed at which the exhaust gas impacts on the tur-
bine wheel is increased, as a result of which the
speed of the turbocharger and thus the charge pres-
sure rises.
At high engine speeds the guide vanes are increas-
ingly opened and the flow cross-section is thus
enlarged, as a result of which the speed of the turbo-
charger reduces and the charge pressure drops.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system consists of the charge air
cooler and charge air cooler piping.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
OPERATION
Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-
ized air from the turbocharger then flows forward
through the charge air cooler located in front of theradiator. From the charge air cooler the air flows
back into the intake manifold.
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS
NOTE: Slight engine oil pooling in the charge air
inlet hose IS NOT premature turbocharger failure.
Slight pooling is the normal result of the breather
system. Test the air breather tube for normal oper-
ation by referring to the appropriate diagnostic
manual.
Fig. 2 TURBOCHARGER COMPONENTS
1 - COMPRESSOR HOUSING
2 - GUIDE VANE
3 - GUIDE STUD OF GUIDE VANE
4 - GUIDE STUD OF CONTROL LINKAGE
5 - CONTROL LINKAGE
6 - ADJUSTING RING
7 - TURBINE HOUSING
8 - BOOST PRESSURE CONTROL UNIT
1A - EXHAUST GASES TO TURBINE WHEEL
2A - TURBO INLET (FRESH AIR)
3A - TURBO OUTLET (COMPRESSED AIR)
4A - EXHAUST OUTLET
11 - 4 EXHAUST SYSTEMVA
TURBOCHARGER SYSTEM (Continued)

Low turbocharger boost pressure and low engine
performance can be caused by leaks in the charge air
cooler or it's plumbing. The following procedure out-
lines how to check for leaks in the charge air cooler
system.
(1) Loosen clamp and remove turbocharger to air
inlet duct rubber sleeve from turbocharger.
(2) Insert Special Tool 8442 Adapter into the rub-
ber sleeve. Tighten existing clamp to 8 N´m (72
in.lbs.).
CAUTION: Do not apply more than 138 kpa (20 psi)
air pressure to the charge air cooler system, sever
damage to the charge air cooler system may occur.
(3) Connect regulated air supply to air fitting on
Special Tool 8442 Adapter. Set air pressure to a Max-
imum of 138 kpa (20 psi).
(4) Using soapy water check the air inlet ducts,
rubber sleeves, charge air cooler and intake manifold
for leaks.
REMOVAL
(1) Remove front bumper.
(2) Remove headlamp assemblies.
(3) Remove front cross member together with front
grille.
(4) Remove left and right radiator trim (Fig. 3).
(5) Disconnect charge air hoses at charge air cooler
(Fig. 3).
(6) Disconnect power steering cooler loop from
charge air cooler (Fig. 3).
(7) Remove charge air cooler from radiator assem-
bly (Fig. 3).
CLEANING
CAUTION: Do not use caustic cleaners to clean the
charge air cooler. Damage to the charge air cooler
will result.
NOTE: If internal debris cannot be removed from
the cooler, the charge air cooler MUST be replaced.
(1) If the engine experiences a turbocharger failure
or any other situation where oil or debris get into the
charge air cooler, the charge air cooler must be
cleaned internally.
(2) Position the charge air cooler so the inlet and
outlet tubes are vertical.
(3) Flush the cooler internally with solvent in the
direction opposite of normal air flow.
(4) Shake the cooler and lightly tap on the end
tanks with a rubber mallet to dislodge trapped
debris.(5) Continue flushing until all debris or oil are
removed.
(6) Rinse the cooler with hot soapy water to
remove any remaining solvent.
(7) Rinse thoroughly with clean water and blow
dry with compressed air.
INSPECTION
Visually inspect the charge air cooler for cracks,
holes, or damage. Inspect the tubes, fins, and welds
for tears, breaks, or other damage. Replace the
charge air cooler if damage is found.
Pressure test the charge air cooler, using Charge
Air Cooler Tester Kit.
INSTALLATION
(1) Install charge air cooler to radiator (Fig. 3).
(2) Connect power steering cooler loop to charge
air cooler (Fig. 3).
(3) Connect charge air hoses (Fig. 3).
(4) Install both radiator trim pieces (Fig. 3).
(5) Install front grille with front cross member.
(6) Install headlamp assemblies.
(7) Install front bumper.
Fig. 3 CHARGE AIR COOLER
1 - POWER STEERING COOLER LOOP
2 - CHARGE AIR HOSE
3 - CHARGE AIR COOLER HOSE
4 - CHARGE AIR COOLER
5 - LEFT RADIATOR TRIM PANEL
6 - RIGHT RADIATOR TRIM PANEL
VAEXHAUST SYSTEM 11 - 5
CHARGE AIR COOLER AND PLUMBING (Continued)

INSTALLATION - LOW PRESSURE PUMP
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
NOTE: Clean sealing surfaces, replace seal if nec-
essary.
(1) Prime the low pressure pump with the appro-
priate fuel.
(2) Attach low pressure fuel pump to cylinder head
front cover. Tighten bolt to 9N´m (80 lbs. in.).
(3) Attach fuel lines to low pressure pump.
(4) Install vacuum pump (Refer to 9 - ENGINE/
ENGINE BLOCK/INTERNAL VACUUM PUMP -
INSTALLATION).
(5) Reconnect negative battery cable.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH FAN. DO NOT PUT YOUR
HANDS NEAR PULLEYS, BELTS OR FAN. DO NOT
WEAR LOOSE CLOTHING.
(6) Start engine and inspect for leaks.
FUEL RAIL
DESCRIPTION
The fuel rail acts like a high pressure store. It is
available to all injectors for drawing fuel which has
been compressed by the injection pump. The rail
pressure sensor, rail pressure solenoid, high pressure
line, and the return flow line are attached to the fuel
rail (Fig. 7).
OPERATION
The stored fuel volume inside the rail acts as a
damper for pressure fluctuations which result
because of pulsating supply and brief large extrac-
tions of fuel during injector firing. The rail primarily
influences the atomization of fuel at the injector noz-
zle, and the accuracy of injected quantity during
injection.
REMOVAL
(Refer to 14 - FUEL SYSTEM - WARNING).
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
(1) Disconnect negative battery cable.
(2) Partially drain cooling system from radiator
only.
(3) Remove thermostat housing.
(4) Disconnect engine wiring electrical connectors
from sensors restricting harness movement.
(5) Remove engine harness retaining bolts.
(6) Remove fuel temperature sensor from fuel rail.
(7) Remove fuel rail retaining bolts and disconnect
glow plug connectors.
(8) Remove front engine lift support.
CAUTION: When slackening and tightening fuel
injection line union nuts, counter hold with wrench
at threaded connection. ON NO ACCOUNT exceed
the tightening torque at any time. Do NOT crimp or
bend lines.
NOTE: After removing lines, seal connections and
ensure cleanliness.
(9) Remove injector high pressure lines (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- REMOVAL) (Fig. 7).
(10) Remove pressure line of high pressure pump
(Fig. 7).
(11) Detach fuel return flow line to high pressure
pump at rail (Fig. 7).
(12) Detach fuel return flow line to fuel filter at
fuel filter (Fig. 7).
(13) Remove fuel rail (Fig. 7).
INSTALLATION
(Refer to 14 - FUEL SYSTEM - WARNING)
WARNING: NO FIRE, FLAMES OR SMOKING. RISK
OF POISONING FROM INHALING OR SWALLOWING
FUEL. RISK OF INJURY TO EYES AND SKIN FROM
CONTACT WITH FUEL. POUR FUELS ONLY INTO
SUITABLE AND APPROPRIATELY MARKED CON-
TAINERS. WEAR PROTECTIVE CLOTHING.
VAFUEL DELIVERY 14 - 11
FUEL PUMP (Continued)

NOTE: Always replace the seals that seal off the
injectors at the cylinder head to the combustion
chamber and replace the retaining screws.
REMOVAL
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 1600BAR (23,200 PSI).
USE EXTREME CAUTION WHEN INSPECTING FOR
HIGH-PRESSURE FUEL LEAKS. FUEL UNDER THIS
AMOUNT OF PRESSURE CAN PENETRATE SKIN
CAUSING PERSONAL INJURY OR DEATH. INSPECT
FOR HIGH-PRESSURE LEAKS WITH A SHEET OF
CARD BOARD. WEAR SAFETY GOGGLES AND
ADEQUATE PROTECTIVE CLOTHING WHEN SER-
VICING FUEL SYSTEM.
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
NOTE: The engine must be lowered in the vehicle to
remove the fourth and fifth cylinders fuel injectors.
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(3) Raise and suitably support the vehicle.
(4) Remove lower radiator deflector plate.
(5) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(6) Remove turbocharger down pipe assembly.
(7) Remove oil dipstick tube retaining bolt and pull
tube from oil pan.
(8) Lower vehicle.
(9) Remove upper radiator hose.
(10) Remove air cleaner box assembly and hoses.
(11) Remove charge air cooler inlet hose.
(12) Remove charge air cooler to turbocharger inlet
adaptor.
(13) Remove turbocharger to right engine mount
bracket.
(14) Disconnect steering coupler at gear box (RHD
Only).
(15) Remove battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - REMOVAL).
(16) Unclip PDC from battery tray and set aside.(17) Remove battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - REMOVAL).
(18) Remove power steering reservoir (Refer to 19 -
STEERING/PUMP/RESERVOIR - REMOVAL).
(19) Remove charger air cooler outlet hose.
(20) Remove intake manifold to left engine mount
bracket.
(21) Evacuate air conditioning system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(22) Disconnect air conditioning suction / discharge
lines at A/C compressor.
(23) Disconnect pedal position sensor electrical
connector.
(24) Unplug injector electrical connectors.
(25) Remove fuel / water separator to intake man-
ifold retaining bolts.
(26) Support engine with hoist.
(27) Remove engine mount through bolts.
(28) Remove right engine mount sill plate.
NOTE: Counterhold injection lines with wrench
socket at threaded connections of injectors.
(29) Disconnect fuel injector high pressure line.
(30) Remove fuel injector retaining bolt and ten-
sion claw.
(31) Suitably lower engine to gain fuel injector
access and remove injector.
NOTE: If injectors are tight, remove with extraction
claw in place of tensioning claw. If extraction claw
contacts cylinder head cover, remove cylinder head
cover. If necessary, remove injectors with threaded
adaptor and discard injector.
(32) Remove injectors (Fig. 10).
(33) Clean injectors and recesses (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/FUEL INJEC-
TOR - STANDARD PROCEDURE).
INSTALLATION
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 1600BAR (23,200 PSI).
USE EXTREME CAUTION WHEN INSPECTING FOR
HIGH-PRESSURE FUEL LEAKS. FUEL UNDER THIS
AMOUNT OF PRESSURE CAN PENETRATE SKIN
CAUSING PERSONAL INJURY OR DEATH. INSPECT
FOR HIGH-PRESSURE LEAKS WITH A SHEET OF
CARD BOARD. WEAR SAFETY GOGGLES AND
ADEQUATE PROTECTIVE CLOTHING WHEN SER-
VICING FUEL SYSTEM.
VAFUEL INJECTION 14 - 23
FUEL INJECTOR (Continued)

(15) Install battery tray(Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(16) Connect PDC to battery tray.
(17) Install battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(18) Connect steering coupler at gear box (RHD
Only).
(19) Install turbocharger to right engine mount
bracket (Refer to 11 - EXHAUST SYSTEM/TURBO-
CHARGER SYSTEM - INSTALLATION).
(20) Install charge air cooler to turbocharger inlet
adaptor (Refer to 11 - EXHAUST SYSTEM/CHARGE
AIR COOLER AND PLUMBING - INSTALLATION) .
(21) Install charger air cooler inlet hose (Refer to
11 - EXHAUST SYSTEM/CHARGE AIR COOLER
AND PLUMBING - INSTALLATION).
(22) Install air cleaner box assembly and hoses.
(23) Install upper radiator hose.
(24) Raise vehicle.
(25) Install dipstick tube into oil pan and tighten
retaining bolt.
(26) Install turbocharger down pipe assembly.
(27) Close cooling system drain.
(28) Install lower radiator deflector plate.
(29) Lower vehicle.
(30) Connect negative battery cable.
(31) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION)..
(32) Fill cooling system with the correct mixture to
the proper level (Refer to 7 - COOLING/ENGINE/
COOLANT - STANDARD PROCEDURE).
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT PUT YOUR
HANDS NEAR PULLEYS, BELTS OR FAN. DO NOT
WEAR LOOSE CLOTHING.
(33) Start engine and inspect for leaks.
(34) Recharge air conditioning system.
FUEL PRESSURE SENSOR
DESCRIPTION
DESCRIPTION
The fuel pressure sensor provides the current low
pressure (the pressure that exist at the inlet of the
high pressure injection pump) fuel pressure to the
ECM (Fig. 11).
The fuel pressure when the engine is idling is
approximately 36 psi (2.5 Bar). The fuel pressure
while driving is 50±58 psi (3.5 - 4.0Bar).
DESCRIPTION
The fuel rail pressure sensor provides the current
fuel rail pressure to the ECM.
OPERATION
OPERATION
A diaphragm and an electric resistance meter are
integrated in the fuel pressure sensor. The non-con-
stant fuel system pressure from the low pressure fuel
pump influences the position of the diaphragm which
in turn alters it's electrical resistance. This resis-
tance is analyzed by the ECM. The ECM then actu-
ates the fuel rail pressure control valve until the
desired rail pressure value is obtained (Fig. 11).
OPERATION
The fuel rail pressure sensor measures the current
fuel rail pressure and sends a voltage signal to the
ECM. The ECM then actuates the fuel rail pressure
control valve solenoid until the desired rail pressure
is achieved.
Fig. 11 FUEL PRESSURE SENSOR
VAFUEL INJECTION 14 - 25
FUEL INJECTOR (Continued)

SPECIFICATIONS - TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Power Steering Pump To
Timing Case Cover/
Support21 15 185
High Pressure Flexible
Hose To Power Steering
Pump38 28 336
Power Steering Pulley To
Pump30 22 265
FLUID
STANDARD PROCEDURE
POWER STEERING PUMP FILL AND BLEED
PROCEDURE
(1) Remove the cap from the fluid reservoir.
Check cap seal for damage and replace if
needed.
(2) Fill the power steering pump with Mopar
ATF+4 Automatic Transmission fluid or equivalent.
Do not fill fluid beyond the MAX mark.
(3) Raise the vehicles front wheels off the ground.
(4) With the engine off turn the steering wheel
from right to left.Perform this step until all the
bubble formations can no longer be seen in the
power steering reservoir.
(5) Start the engine and turn the steering wheel
with the engine at idle speed then shut the engine off
and check for correct oil level and no bubble in the
system.
(6) Reinstall power steering cap tightly.
(7) Test the system for leaks and proper operation.
FLUID COOLER TUBE
REMOVAL
(1) Siphon as much power steering fluid as possi-
ble out of the reservoir.
(2) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(3) Remove the left headlight assembly.
(4) Disconnect the return lines from the cooler
tube.
(5) Remove the radiator clips (2).
(6) Remove the heat shield bolt for the turbo at
the core support.
(7) Remove the right headlight assembly.(8) Remove the core support bolts (4) and discon-
nect the hood latch cable.
(9) Remove the fan bracket bolts (4) to the radiator
(Fig. 2).
(10) Remove the two upper screws for the con-
denser (Fig. 2).
(11) Remove the condenser air dam shield.
(12) Remove the mounting screws for the cooler
tube (Fig. 2).
(13) Remove the cooler tube from the vehicle.
INSTALLATION
(1) Install the cooler tube to the vehicle.
(2) Install the cooler tube mounting screws (Fig.
2).
(3) Install the condenser air dam shield.
(4) Install the condenser upper mounting screws
(Fig. 2).
Fig. 2 FLUID COOLER TUBE
1 - MOUNTING SCREWS (4)
2 - FLUID COOLER
3 - ELECTRIC COOLING FAN
4 - A/C CONDENSOR
19 - 14 PUMPVA
PUMP (Continued)

(5) Install the fan bracket bolts to the radiator
(Fig. 2).
(6) Install the core support bolts and reconnect the
hood latch cable.
(7) Install the right headlight assembly.
(8) Install the bolt for the turbo shield at the core
support.
(9) Install the radiator clips.
(10) Install the return lines to the cooler tube.
(11) Install the left headlight assembly.
(12) Install the grille assembly (Refer to 23 -
BODY/EXTERIOR/GRILLE - INSTALLATION).
(13) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP/FLUID - STANDARD PROCE-
DURE).
HOSES
REMOVAL
REMOVAL - PRESSURE HOSE
(1) Siphon as much power steering fluid as possi-
ble out of the reservoir.
(2) Disconnect the pressure hose at the pump.
(3) Disconnect the pressure hose at the steering
gear.
(4) Remove the pressure hose mounting bracket
from the gear.
(5) Remove the pressure hose from the vehicle.
REMOVAL - RETURN LINE FROM PUMP TO
COOLER TUBE
(1) Siphon as much power steering fluid as possi-
ble out of the reservoir.
(2) Disconnect the return line at the pump.
(3) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(4) Remove the left headlight assembly.
(5) Disconnect the return line at the cooler tube.
(6) Remove the return line from the vehicle.
REMOVAL - RETURN HOSE FROM GEAR TO
COOLER TUBE
(1) Siphon as much power steering fluid as possi-
ble out of the reservoir.
(2) Disconnect the return hose from the gear.(3) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(4) Remove the left headlight assembly.
(5) Disconnect the return line at the cooler tube.
(6) Remove the return line from the vehicle.
INSTALLATION
INSTALLATION - PRESSURE HOSE
(1) Install the pressure hose to the vehicle.
(2) Reconnect the pressure hose at the steering
gear. Tighten to 37 N´m (27 ft.lbs.).
(3) Install the pressure hose mounting bracket to
the steering gear.
(4) Reconnect the pressure hose at the power
steering pump. Tighten to 38 N´m (28 ft.lbs.).
(5) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP/FLUID - STANDARD PROCE-
DURE).
INSTALLATION - RETURN LINE FROM PUMP
TO COOLER TUBE
(1) Install the return line to the vehicle.
(2) Reconnect the return line at the cooler tube.
(3) Install the left headlight assembly.
(4) Install the grille assembly (Refer to 23 - BODY/
EXTERIOR/GRILLE - INSTALLATION).
(5) Reconnect the return line at the power steering
pump.
(6) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP/FLUID - STANDARD PROCE-
DURE).
INSTALLATION - RETURN HOSE FROM GEAR
TO COOLER TUBE
(1) Install the return line to the vehicle.
(2) Reconnect the return line at the cooler tube.
(3) Install the left headlight assembly.
(4) Install the grille assembly (Refer to 23 - BODY/
EXTERIOR/GRILLE - INSTALLATION).
(5) Reconnect the return line at the power steering
gear.
(6) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP/FLUID - STANDARD
PROCEDURE).
VAPUMP 19 - 15
FLUID COOLER TUBE (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - 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 main 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.
DIAGNOSIS AND TESTING - 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 failuredue 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
STANDARD PROCEDURE - CHECK OIL LEVEL
(1) Verify that the vehicle is parked on a level sur-
face.
(2) Remove locking pin (1) (Fig. 136). 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.
Fig. 136 Remove Dipstick Tube Cap Lock
1 - LOCKING PIN
2 - TUBE CAP
3 - DIPSTICK TUBE
21 - 102 AUTOMATIC TRANSMISSION - NAG1VA
FLUID AND FILTER (Continued)