gas type DODGE RAM 2001 Service Repair Manual

²BE6=15004X4
²BR2=25004X2
²BE2=25004X2
²BR7=25004X4
²BE7=25004X4
²BR3=35004X2
²BE3=35004X2
²BR8=35004X4
²BE8=35004X4
DIGIT 19
Price Class
²L = Ram Truck (All)
DIGITS 20 AND 21
Body Type
²
31 = Ram Truck Club Cab (138.7 in. Wheel Base)
²32 = Ram Truck Club Cab (154.7 in. Wheel Base)
²33 = Ram Truck Quad Cab (138.7 in. Wheel Base)
²34 = Ram Truck Quad Cab (154.7 in. Wheel Base)
²61 = Ram Truck (118.7 in. Wheel Base)
²62 = Ram Truck (134.7 in. Wheel Base)
²63 = Ram Truck Cab Chassis (138.7 in. Wheel
Base)
²
64 = Ram Truck Cab Chassis (162.7 in. Wheel
Base)
BODY CODE PLATEÐLINE 3
DIGITS 1,2, AND 3
Paint Procedure
²APA = Monotone
²AP9 = Special
²APB = Two-tone (Waterfall)
²APC = Two-tone (Centerband)
²APD = Two-tone (Lower break)
DIGIT 4
Open Space
DIGITS 5 THROUGH 8
Primary Paint
Refer to Group 23, Body for color codes.
DIGIT 9
Open Space
DIGITS 10 THROUGH 13
Secondary Paint
DIGIT 14
Open Space
DIGITS 15 THROUGH 18
Interior Trim CodeDIGIT 19
Open Space
DIGITS 20, 21, AND 22
Engine Code
²EHC = 3.9 L 6 cyl. MPI Gasoline
²ELF = 5.2 L 8 cyl. MPI Gasoline
²ELN = 5.2 L 8 cyl. (CNG)
²EML = 5.9 L 8 cyl. MPI Gasoline
²EMM = 5.9 L 8 cyl. MPI Gasoline (Heavy Duty)
²ETC = 5.9 L 6 cyl. Turbo Diesel
²EWA = 8.0 L 10 cyl. MPI Gasoline
BODY CODE PLATEÐLINE 2
DIGIT 1 Open Space
DIGITS 2 AND 3 Species Code. (Used for Manufacturing)
DIGIT 4
Open Space
DIGIT 5
Market Code
²B = International
²C = Canada
²M = Mexico
²U = United States
DIGIT 6
Open Space
DIGITS 7 THROUGH 23
Vehicle Identification Number (VIN)
Refer to Vehicle Identification Number (VIN) para-
graph for proper breakdown of VIN code.
BODY CODE PLATEÐLINE 1
DIGITS 1 THROUGH 6 Body-in-white assembly sequence.
DIGIT 7
Open Space
DIGIT 8 Tailgate trim code.
DIGIT 9
Open Space
DIGITS 10 THROUGH 12 Cargo box code
²XBS = Sweptline
DIGIT 13
Open Space
2 INTRODUCTIONBR/BE
BODY CODE PLATE (Continued)

LUBRICATION & MAINTENANCE
TABLE OF CONTENTS
page page
LUBRICATION & MAINTENANCE
DESCRIPTION............................1
INTERNATIONAL SYMBOLS
DESCRIPTION............................3
PARTS & LUBRICANT RECOMMENDATION
STANDARD PROCEDURE...................3
FLUID TYPES
DESCRIPTION............................3
OPERATION.............................5
FLUID CAPACITIES
SPECIFICATIONS.........................6MAINTENANCE SCHEDULES
DESCRIPTION............................7
JUMP STARTING
STANDARD PROCEDURE..................27
HOISTING
STANDARD PROCEDURE..................28
TOWING
STANDARD PROCEDURE..................29
LUBRICATION &
MAINTENANCE
DESCRIPTION - FUEL REQUIREMENTS - GAS
ENGINES
Your engine is designed to meet all emissions reg-
ulations and provide excellent fuel economy and per-
formance when using high quality unleaded gasoline
having an octane rating of 87. The use of premium
gasoline is not recommended. The use of premium
gasoline will provide no benefit over high quality reg-
ular gasoline, and in some circumstances may result
in poorer performance.
Light spark knock at low engine speeds is not
harmful to your engine. However, continued heavy
spark knock at high speeds can cause damage and
immediate service is required. Engine damage result-
ing from operation with a heavy spark knock may
not be covered by the new vehicle warranty.
Poor quality gasoline can cause problems such as
hard starting, stalling and hesitations. If you experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle.
Over 40 auto manufacturers world-wide have
issued and endorsed consistent gasoline specifications
(the Worldwide Fuel Charter, WWFC) to define fuel
properties necessary to deliver enhanced emissions,
performance and durability for your vehicle. We rec-
ommend the use of gasolines that meet the WWFC
specifications if they are available.
REFORMULATED GASOLINE
Many areas of the country require the use of
cleaner burning gasoline referred to as ªreformulat-
edº gasoline. Reformulated gasoline contain oxygen-
ates, and are specifically blended to reduce vehicle
emissions and improve air quality.
We strongly supports the use of reformulated gas-
oline. Properly blended reformulated gasoline will
provide excellent performance and durability for the
engine and fuel system components.
GASOLINE/OXYGENATE BLENDS
Some fuel suppliers blend unleaded gasoline with
oxygenates such as 10% ethanol, MTBE, and ETBE.
Oxygenates are required in some areas of the country
during the winter months to reduce carbon monoxide
emissions. Fuels blended with these oxygenates may
be used in your vehicle.
CAUTION: DO NOT use gasoline containing METH-
ANOL. Gasoline containing methanol may damage
critical fuel system components.
MMT IN GASOLINE
MMT is a manganese-containing metallic additive
that is blended into some gasoline to increase octane.
Gasoline blended with MMT provide no performance
advantage beyond gasoline of the same octane number
without MMT. Gasoline blended with MMT reduce
spark plug life and reduce emission system perfor-
mance in some vehicles. We recommend that gasolines
free of MMT be used in your vehicle. The MMT con-
tent of gasoline may not be indicated on the gasoline
pump; therefore, you should ask your gasoline retailer
whether or not his/her gasoline contains MMT.
BR/BELUBRICATION & MAINTENANCE 0 - 1

INTERNATIONAL SYMBOLS
DESCRIPTION
DaimlerChrysler Corporation uses international
symbols to identify engine compartment lubricant
and fluid inspection and fill locations (Fig. 1).
PARTS & LUBRICANT
RECOMMENDATION
STANDARD PROCEDURE - CLASSIFICATION OF
LUBRICANTS
Only lubricants that are endorsed by the following
organization should be used to service a Daimler-
Chrysler Corporation vehicle.
²Society of Automotive Engineers (SAE)
²American Petroleum Institute (API) (Fig. 4)
²National Lubricating Grease Institute (NLGI)
(Fig. 2)
Lubricating grease is rated for quality and usage
by the NLGI. All approved products have the NLGI
symbol (Fig. 2) on the label. At the bottom NLGI
symbol is the usage and quality identification letters.
Wheel bearing lubricant is identified by the letter
ªGº. Chassis lubricant is identified by the latter ªLº.
The letter following the usage letter indicates the
quality of the lubricant. The following symbols indi-
cate the highest quality.
When service is required, DaimlerChrysler Corpo-
ration recommends that only Mopartbrand parts,
lubricants and chemicals be used. Mopar provides
the best engineered products for servicing Daimler-
Chrysler Corporation vehicles.
FLUID TYPES
DESCRIPTION - ENGINE OIL
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conform to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 or 10W-30. These oils
are specified with a dual SAE viscosity grade which
indicates the cold-to-hot temperature viscosity range.
Select an engine oil that is best suited to your par-
ticular temperature range and variation (Fig. 3).
Fig. 1 International Symbols
Fig. 2 NLGI Symbol
1 - WHEEL BEARINGS
2 - CHASSIS LUBRICATION
3 - CHASSIS AND WHEEL BEARINGS
BR/BELUBRICATION & MAINTENANCE 0 - 3

ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 4).
DESCRIPTIONÐENGINE OIL
API SERVICE GRADE CERTIFIED
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.Standard engine-oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans.
In diesel engines, use an engine oil that conforms
to API Service Grade CF-4 or CG-4/SH (Fig. 5).
MOPARtprovides an engine oil that conforms to this
particular grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. SAE 15W±40 specifies a multiple
viscosity engine oil.
When choosing an engine oil, consider the range of
temperatures the vehicle will be operated in before
the next oil change. Select an engine oil that is best
suited to your area's particular ambient temperature
range and variation. For diesel engines, refer to (Fig.
6).
Fig. 3 Temperature/Engine Oil Viscosity - 3.2/3.5L
Engine
Fig. 4 API Symbol
Fig. 5 API Service Grade Certification LabelÐDiesel
Engine Oil
Fig. 6 Engine Oil Viscosity RecommendationÐ
Diesel Engines
0 - 4 LUBRICATION & MAINTENANCEBR/BE
FLUID TYPES (Continued)

AXLE SHAFTS
REMOVAL
(1) Remove the axle shaft flange bolts.
(2) Slide the axle shaft out from the axle tube.
INSTALLATION
(1) Clean the gasket contact surface area on the
flange with an appropriate solvent. Install a new
flange gasket and slide the axle shaft into the tube.
(2) Install the bolts and tighten to 129 N´m (95 ft.
lbs.).
AXLE BEARINGS
REMOVAL
(1) Remove wheel and tire assembly.
(2) Remove brake drum.
(3) Remove the axle shaft.
(4) Remove the lock wedge and adjustment nut.
Use Socket DD-1241±JD to remove the adjustment
nut.
(5) Remove the hub assembly. The outer axle bear-
ing will slide out as the hub is being removed.
(6) Remove inner grease seal and discard. Use
Installer 5064 and Handle C-4171 to drive grease
seal and inner axle bearing from the hub.
(7) Remove the bearing cups from the hub bore.
Use a brass drift, or an appropriate removal tool, to
tap out the cups.
INSTALLATION
(1) Thoroughly clean both axle bearings and inte-
rior of the hub with an appropriate cleaning solvent.
(2) Install bearing cups with Installer 8151 and
Handle C-4171.
(3)Pack inner and outer bearings with
Mopar wheel bearing grease or equivalent.
(4) Apply grease to inner and outer bearing cup
surfaces.
(5) Install inner axle bearing in the hub.
(6) Installnewgrease seal in hub with Installer
8149 and Handle C-4171.(7) Inspect bearing and seal contact surfaces on
the axle tube for burrs/roughness. Remove all the
rough contact surfaces from the axle tube.
(8) Carefully slide the hub onto the axle.
CAUTION: Do not let grease seal contact axle tube
threads during installtion.
(9) Install outer axle bearing.
(10) Install hub bearing adjustment nut with
Socket DD-1241±JD.
(11) Tighten adjustment nut to 163-190 N´m (120-
140 ft. lbs.) while rotating the wheel. Then loosen
adjustment nut 1/8 to 1/3 of-a-turn to provide 0.025-
0.250mm (0.001-0.009 in.) wheel bearing end play.
(12) Tap locking wedge into the spindle keyway
and adjustment nut.
NOTE: Located locking wedge in a new position in
the adjustment nut.
(13) Install axle shaft and brake drum.
(14) Install the wheel and tire assembly.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Scribe a mark on the universal joint, pinion
yoke, and pinion shaft for reference.
(3) Disconnect the propeller shaft from the pinion
yoke. Secure the propeller shaft in an upright posi-
tion to prevent damage to the rear universal joint.
(4) Remove the wheel and tire assemblies.
(5) Remove the brake drums to prevent any drag.
The drag may cause a false bearing preload torque
measurement.
(6) Rotate the pinion yoke three or four times.
(7) Measure the amount of torque necessary to
rotate the pinion gear with a (in. lbs.) dial-type
torque wrench. Record the torque reading for instal-
lation reference.
(8) Hold the yoke with Wrench 6719. Remove the
pinion shaft nut and washer.
(9) Remove the yoke with Remover C-452 (Fig. 22).
(10) Remove the pinion shaft seal with suitable
pry tool or slide-hammer mounted screw.
INSTALLATION
NOTE: The outer perimeter of the seal is pre-coated
with a special sealant. An additional application of
sealant is not required.
(1) Apply a light coating of gear lubricant on the
lip of pinion seal.
Arbor Discs 6732
BR/BEREAR AXLE - 248RBI 3 - 125
REAR AXLE - 248RBI (Continued)

AXLE SHAFTS
REMOVAL
(1) Remove the axle shaft flange bolts.
(2) Slide the axle shaft out from the axle tube.
INSTALLATION
(1) Clean the gasket contact surface area on the
flange with an appropriate solvent. Install a new
flange gasket and slide the axle shaft into the tube.
(2) Install the bolts and tighten to 129 N´m (95 ft.
lbs.).
AXLE BEARINGS
REMOVAL
(1) Remove wheel and tire assembly.
(2) Remove brake drum.
(3) Remove the axle shaft.
(4) Remove the lock wedge and adjustment nut.
Use Socket DD-1241±JD to remove the adjustment
nut.
(5) Remove the hub assembly. The outer axle bear-
ing will slide out as the hub is being removed.
(6) Remove inner grease seal and discard. Use
Installer 5064 and Handle C-4171 to drive grease
seal and inner axle bearing from the hub.
(7) Remove the bearing cups from the hub bore.
Use a brass drift, or an appropriate removal tool, to
tap out the cups.
INSTALLATION
(1) Thoroughly clean both axle bearings and inte-
rior of the hub with an appropriate cleaning solvent.
(2) Install bearing cups with Installer 8151 and
Handle C-4171.
(3)Pack inner and outer bearings with
Mopar wheel bearing grease or equivalent.
(4) Apply grease to inner and outer bearing cup
surfaces.
(5) Install inner axle bearing in the hub.
(6) Installnewgrease seal in hub with Installer
8149 and Handle C-4171.
(7) Inspect bearing and seal contact surfaces on
the axle tube for burrs/roughness. Remove all the
rough contact surfaces from the axle tube.
(8) Carefully slide the hub onto the axle.
CAUTION: Do not let grease seal contact axle tube
threads during installtion.
(9) Install outer axle bearing.
(10) Install hub bearing adjustment nut with
Socket DD-1241±JD.(11) Tighten adjustment nut to 163-190 N´m (120-
140 ft. lbs.) while rotating the wheel. Then loosen
adjustment nut 1/8 to 1/3 of-a-turn to provide 0.025-
0.250mm (0.001-0.009 in.) wheel bearing end play.
(12) Tap locking wedge into the spindle keyway
and adjustment nut.
NOTE: Located locking wedge in a new position in
the adjustment nut.
(13) Install axle shaft and brake drum.
(14) Install the wheel and tire assembly.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Scribe a mark on the universal joint, pinion
yoke, and pinion shaft for reference.
(3) Disconnect the propeller shaft from the pinion
yoke. Secure the propeller shaft in an upright posi-
tion to prevent damage to the rear universal joint.
(4) Remove the wheel and tire assemblies.
(5) Remove the brake drums to prevent any drag.
The drag may cause a false bearing preload torque
measurement.
(6) Rotate the pinion yoke three or four times.
(7) Measure the amount of torque necessary to
rotate the pinion gear with a (in. lbs.) dial-type
torque wrench. Record the torque reading for instal-
lation reference.
(8) Hold the yoke with Wrench 6719. Remove the
pinion shaft nut and washer.
(9) Remove the yoke with Remover C-452 (Fig. 22).
Fig. 22 Yoke Removal
1 - PINION YOKE
2 - REMOVER C452
3 - 156 REAR AXLE - 267RBIBR/BE

AXLE SHAFTS
REMOVAL
(1) Remove the axle shaft flange bolts.
(2) Slide the axle shaft out from the axle tube.
INSTALLATION
(1) Clean the gasket contact surface area on the
flange with an appropriate solvent. Install a new
flange gasket and slide the axle shaft into the tube.
(2) Install the bolts and tighten to 129 N´m (95 ft.
lbs.).
AXLE BEARINGS
REMOVAL
(1) Remove wheel and tire assembly.
(2) Remove brake drum.
(3) Remove the axle shaft.
(4) Remove the lock wedge and adjustment nut.
Use Socket DD-1241±JD to remove the adjustment
nut.
(5) Remove the hub assembly. The outer axle bear-
ing will slide out as the hub is being removed.
(6) Remove inner grease seal and discard. Use
Installer 5064 and Handle C-4171 to drive grease
seal and inner axle bearing from the hub.
(7) Remove the bearing cups from the hub bore.
Use a brass drift, or an appropriate removal tool, to
tap out the cups.
INSTALLATION
(1) Thoroughly clean both axle bearings and inte-
rior of the hub with an appropriate cleaning solvent.
(2) Install the bearing cups. Use Installer 8153
and Handle C-4171 to install the bearing cups.
(3) Apply lubricant to surface area of the bearing
cup.
(4) Install the inner axle bearing in the hub.
(5) Install a new bearing grease seal. Use Installer
8152 and Handle C-4171 to install the grease seal.
(6) Inspect the bearing and seal contact surfaces
on the axle tube spindle for burrs and/or roughness.
Remove all the rough contact surfaces from the axle
spindle. Apply a coating of multi-purpose NLGI,
grade 2, EP-type lubricant to the axle.
CAUTION: Use care to prevent the bearing grease
seal from contacting the axle tube spindle threads
during installation. Otherwise, the seal could be
damaged.
(7) Carefully slide the hub onto the axle.
(8) Install the outer axle bearing.(9) Install the hub bearing adjustment nut. Use
Socket DD-1241±JD to install the adjustment nut.
(10) Tighten the adjustment nut to 163-190 N´m
(120-140 ft. lbs.) while rotating the wheel.
(11) Loosen the adjustment nut 1/8 of-a-turn to
provide 0.001-inch to 0.010-inch wheel bearing end
play.
(12) Tap the locking wedge into the spindle key-
way and adjustment nut. Try to ensure that the lock-
ing wedge is installed into a new position in the
adjustment nut.
(13) Install the axle shaft.
(14) Install the brake drum.
(15) Install the wheel and tire assembly.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Scribe a mark on the universal joint, pinion
yoke, and pinion shaft for reference.
(3) Disconnect the propeller shaft from the pinion
yoke. Secure the propeller shaft in an upright posi-
tion to prevent damage to the rear universal joint.
(4) Remove the wheel and tire assemblies.
(5) Remove the brake drums to prevent any drag.
The drag may cause a false bearing preload torque
measurement.
(6) Rotate the pinion yoke three or four times.
(7) Measure the amount of torque necessary to
rotate the pinion gear with a (in. lbs.) dial-type
torque wrench. Record the torque reading for instal-
lation reference.
(8) Hold the yoke with Wrench 6719. Remove the
pinion shaft nut and washer.
(9) Remove the yoke with Remover C-452 (Fig. 22).
(10) Remove the pinion shaft seal with suitable
pry tool or slide-hammer mounted screw.
INSTALLATION
(1) Clean the seal contact surface in the housing
bore.
(2) Examine the splines on the pinion shaft for
burrs or wear. Remove any burrs and clean the shaft.
(3) Inspect pinion yoke for cracks, worn splines
and worn seal contact surface. Replace yoke if neces-
sary.
NOTE: The outer perimeter of the seal is pre-coated
with a special sealant. An additional application of
sealant is not required.
(4) Apply a light coating of gear lubricant on the
lip of pinion seal.
(5) Install new pinion shaft seal with an appropri-
ate Installer.
BR/BEREAR AXLE - 286RBI 3 - 185

RELEASE
REMOVAL..............................40
INSTALLATION...........................41SHOES
REMOVAL..............................41
INSTALLATION...........................42
BRAKES - BASE
SPECIFICATIONS
BASE BRAKE
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Front/Rear Disc Brake
Caliper
TypeDual Piston Sliding
Front Disc Brake Caliper
Piston Diameter LD54 mm (2.00 in.)
Front Disc Brake Caliper
Piston Diameter HD56 mm (2.00 in.)
Front Disc Brake Rotor
1500 4x2304ý30 mm (11.96ý1.18
in.)
Front Disc Brake Rotor
1500 4x4307.5ý30 mm
(12.10ý1.18 in.)
Front Disc Brake Rotor
2500/3500326.5ý36 mm (12.5ý1.5
in.)
Front/Rear Disc Brake
Rotor
Max. Runout0.127 mm (0.005 in.)
Front/Rear Disc Brake
Rotor
Max. Thickness Variation0.025 mm (0.001 in.)
Mininium Front Rotor
Thickness
150028.39 mm (1.117 in.)
Minimum Front Rotor
Thickness
2500/350033.90 mm (1.334 in.)
Mininium Rear Rotor
Thickness
2500/350028.39 mm (1.117 in.)
DESCRIPTION SPECIFICATION
Drum Brake
Size
1500279ý57 mm (11ý2.25 in.)
Drum Brake
Size
2500/3500308ý89 mm (12.125ý3.5
in.)
Drum Brake
Max. Runout
15000.18 mm (0.007 in.)
Drum Brake
Max. Thickness Variation
15000.076 mm (0.003 in.)
Rear Disc Brake Caliper
25002x45 mm (1.77 in)
Rear Disc Brake Caliper
35002x51 mm (2.00 in)
Rear Disc Brake Rotor
2500/3500323.5x30 mm (1.18 in)
Wheel Cylinder Bore Size
150025.4 mm (1.00 in.)
Wheel Cylinder Bore Size
2500/350025.4 mm (1.00 in.)
Brake Booster
Type
1500/2500 Gasoline
EnginesVacuum Dual Diaphragm
Brake Booster
Type
All 3500/
2500 Diesel Engines
OnlyHydraulic
5 - 2 BRAKESBR/BE

(10) Push caliper mounting bolt bushings out of
the boot seals and remove the boot seals from the
caliper (Fig. 11).
(11) Remove caliper bleed screw.
CLEANING
Clean the caliper components with clean brake
fluid or brake clean only. Wipe the caliper and piston
dry with lint free towels or use low pressure com-
pressed air.
CAUTION: Do not use gasoline, kerosene, thinner,
or similar solvents. These products may leave a
residue that could damage the piston and seal.
INSPECTION
The piston is made from a phenolic resin (plastic
material) and should be smooth and clean.
The piston must be replaced if cracked or scored.
Do not attempt to restore a scored piston surface by
sanding or polishing.
CAUTION: If the caliper piston is replaced, install
the same type of piston in the caliper. Never inter-
change phenolic resin and steel caliper pistons.
The pistons, seals, seal grooves, caliper bore and
piston tolerances are different.
The bore can belightlypolished with a brake
hone to remove very minor surface imperfections
(Fig. 12). The caliper should be replaced if the bore is
severely corroded, rusted, scored, or if polishing
would increase bore diameter more than 0.025 mm
(0.001 inch).
ASSEMBLY
CAUTION: Dirt, oil, and solvents can damage cali-
per seals. Insure assembly area is clean and dry.
(1) Lubricate caliper pistons, piston seals and pis-
ton bores with clean, fresh brake fluid.
(2) Install new piston seals into caliper bores (Fig.
13).
NOTE: Verify seal is fully seated and not twisted.
(3) Lightly lubricate lip of new boot with silicone
grease. Install boot on piston and work boot lip into
the groove at the top of piston.
Fig. 9 Piston Dust Boot Removal
1 - CALIPER
2 - DUST BOOT
Fig. 10 Piston Seal
1 - CALIPER
2 - PISTON BORE
3 - PISTON SEAL
Fig. 11 Bushings And Boot Seals
1 - CALIPER
2 - BUSHING
3 - BOOT SEAL
5 - 12 BRAKESBR/BE
DISC BRAKE CALIPERS (Continued)

ENGINE COOLANT
THERMOSTAT - 3.9L/5.2L/5.9L
DESCRIPTION
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
The thermostat on the 3.9L, 5.2L and 5.9L gas
powered engines is located beneath the thermostat
housing at the front of the intake manifold (Fig. 15).
The thermostat is a wax pellet driven, reverse pop-
pet choke type.
Coolant leakage into the pellet container will cause
the thermostat to fail in the open position. Thermo-
stats very rarely stick. Do not attempt to free a ther-
mostat with a prying device.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes longer engine
warmup time, unreliable warmup performance,
increased exhaust emissions and crankcase condensa-
tion that can result in sludge formation.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, the
pellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes. For other DTC numbers, (Refer to 25 - EMIS-
SIONS CONTROL - DESCRIPTION).
The DTC can also be accessed through the DRB
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures information for diagnostic informa-
tion and operation of the DRB scan tool.
REMOVAL
WARNING: DO NOT LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND PRESSURIZED.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
If thermostat is being replaced, be sure that
replacement is specified thermostat for vehicle model
and engine type.
Factory installed thermostat housings on 3.9L,
5.2L and 5.9L engines are installed on a gasket with
an anti-stick coating. This will aid in gasket removal
and clean-up.
(1) Disconnect negative battery cable at battery.
(2) Drain cooling system until coolant level is
below thermostat (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(3) Air Conditioned vehicles: Remove support
bracket (generator mounting bracket-to-intake mani-
fold) located near rear of generator (Fig. 16).
NOTE: On air conditioning equipped vehicles, the
generator must be partially removed.
Fig. 15 ThermostatÐ5.2L and 5.9L Gas Powered
Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
BR/BEENGINE 7 - 49