2003 DODGE RAM app

(7) Back off nut about 30É and align next hub nut
key slot with axle tube key slot and install locking
key.
NOTE: End play should be 0.025-0.25 mm
(0.01-0.001 in.)
(8) Install retainer ring with ring end in the key
slot.
(9) Install new axle shaft gasket and install the
axle shaft.
PINION SEAL
REMOVAL
(1) Remove axle shafts.
(2) Mark the propeller shaft and pinion flange for
installation reference.
(3) Remove propeller shaft.
(4) Rotate pinion gear three or four times.
(5) Measure and record the amount of torque nec-
essary to rotate the pinion gear with an inch pound
torque wrench (Fig. 20).
(6) Hold pinion flange with Flange Wrench 8979
(Fig. 21) and remove pinion flange nut.
(7) Remove pinion flange with Pinion Flange
Puller 8992 (Fig. 22).
(8) Remove pinion shaft seal with a pry tool or
slide hammer mounted screw.
INSTALLATION
(1) Installnewpinion seal with Installer 8896
(Fig. 23).
(2) Apply a light coat of teflon sealant to the pin-
ion flange splines.
(3) Lightly tap the pinion flange onto the pinion
until a few threads are showing.
(4) Install flange washer andnewpinion nut.
(5) Hold pinion flange with Flange Wrench 8979
(Fig. 24) and tighten pinion nut until pinion end play
is taken up.
(6) Rotate pinion several times to seat bearings.
(7) Measure pinion rotating torque with an inch
pound torque wrench and compare it to recorded
measurement. Tighten pinion nut in small incre-
Fig. 20 PINION ROTATING TORQUE
1 - PINION FLANGE
2 - TORQUE WRENCH
Fig. 21 FLANGE WRENCH
1 - PINION FLANGE
2 - FLANGE WRENCH
Fig. 22 PINION FLANGE PULLER
1 - PINION FLANGE
2 - PULLER
3 - 140 REAR AXLE - 11 1/2 AADR
AXLE BEARINGS (Continued)

ments, until pinion rotating torque is 0.40-0.57 N´m
(3-5 in. lbs.) greater than recorded measurement.
(8) Rotate pinion several times then verify pinion
rotating torque again.
(9) Install axle shafts.
(10) Install propeller shaft with reference marks
aligned.
(11) Check differential fluid level.
DIFFERENTIAL
DESCRIPTION
The differential case is a one-piece design. The dif-
ferential pinion shaft is retained with a snap ring.
Differential bearing preload and ring gear backlash
is adjusted by the use of adjusters. The adjuster are
between the differential bearings and the differential
housing. Pinion bearing preload is set and main-
tained by the use of a collapsible spacer. The
stamped steel cover provides a means for inspection
and servicing the differential.
OPERATION
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 25).
When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
26). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
Fig. 23 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 24 FLANGE WRENCH
1 - FLANGE WRENCH
2 - PINION FLANGE
Fig. 25 DIFFERENTIAL-STRAIGHT AHEAD DRIVING
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
Fig. 26 DIFFERENTIAL-ON TURNS
1 - PINION GEARS ROTATE ON PINION SHAFT
DRREAR AXLE - 11 1/2 AA 3 - 141
PINION SEAL (Continued)

(7) Install pinion into the housing and place front
pinion bearing onto the pinion shaft. Draw the pinion
shaft into the front bearing with Installer 8981 (Fig.
60).
(8) Installnewpinion seal (Fig. 61) with Installer
8896 and Handle C-4171.
(9) Apply a light coat of teflon sealant to the pin-
ion flange splines.
(10) Hold pinion and lightly tap the pinion flange
onto the pinion, until a few threads are showing.
(11) Install pinion flange washer andnewpinion
nut.
(12) Hold pinion flange with Flange Wrench 8979
(Fig. 62) and tighten pinion nut until pinion end play
is taken up.
(13) Rotate pinion several times to seat bearings.
(14) Measure pinion rotating torque with an inch
pound torque wrench (Fig. 63). Tighten pinion nut in
small increments until pinion rotating torque is:²New Pinion Bearings:1.7-2.8 N´m (15-25 in.
lbs.)
²Original Pinion Bearings:1.1-2.2 N´m (10-20
in. lbs.)
(15) Rotate pinion several times then verify pinion
rotating torque again.
(16) Position the ring gear on differential case and
start twonewring gear bolts.
(17) Install the rest of thenewring gear bolts and
tighten them alternately to seat the ring gear.
(18) Torque ring gear bolts to 237 N´m (175 ft.
lbs.).
Fig. 60 PINION GEAR INSTALLER
1 - INSTALLER
2 - DIFFERENTIAL HOUSING
Fig. 61 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 62 FLANGE WRENCH
1 - FLANGE WRENCH
2 - PINION FLANGE
Fig. 63 PINION ROTATING TORQUE
1 - PINION FLANGE
2 - TORQUE WRENCH
3 - 152 REAR AXLE - 11 1/2 AADR
PINION GEAR/RING GEAR/TONE RING (Continued)

DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER...........20
STANDARD PROCEDURE - MASTER
CYLINDER BLEEDING..................20
REMOVAL
REMOVAL - ALL EXCEPT HYDROBOOST . . . 21
REMOVAL - HYDROBOOST.............21
INSTALLATION
INSTALLATION - ALL EXCEPT
HYDROBOOST.......................22
INSTALLATION - HYDROBOOST..........22
PEDAL
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................23
INSTALLATION.........................23
ADJUSTABLE PEDAL MOTOR
DESCRIPTION.........................24
REMOVAL.............................24
INSTALLATION.........................24
POWER BRAKE BOOSTER
DESCRIPTION.........................25
OPERATION...........................25
REMOVAL.............................25
INSTALLATION.........................25
HYDRO-BOOST BRAKE BOOSTER
DIAGNOSIS AND TESTING - HYDRAULIC
BOOSTER...........................25
STANDARD PROCEDURE - BLEEDING......27
REMOVAL.............................27
INSTALLATION.........................27
ROTORS
REMOVAL
REMOVAL - REAR.....................28
REMOVAL - FRONT....................28
INSTALLATION
INSTALLATION - REAR.................28
INSTALLATION - FRONT................29SUPPORT PLATE
REMOVAL.............................29
INSTALLATION.........................29
PARKING BRAKE
DESCRIPTION.........................30
OPERATION...........................30
CABLES
REMOVAL
REMOVAL - FRONT PARKING BRAKE
CABLE..............................31
REMOVAL - REAR PARK BRAKE CABLE . . . 31
REMOVAL - RIGHT REAR CABLE.........31
REMOVAL - LEFT REAR CABLE..........32
INSTALLATION
INSTALLATION - FRONT PARKING BRAKE
CABLE..............................32
INSTALLATION - REAR PARK BRAKE
CABLE..............................32
INSTALLATION - RIGHT REAR CABLE.....32
INSTALLATION - LEFT REAR CABLE......33
SHOES
REMOVAL.............................33
CLEANING - REAR DRUM IN HAT BRAKE....33
INSPECTION - REAR DRUM IN HAT BRAKE . . 33
INSTALLATION.........................34
ADJUSTMENTS
ADJUSTMENT - PARKING BRAKE SHOES . . 34
ADJUSTMENT - WITH ADJUSTING TOOL . . . 36
PEDAL
REMOVAL.............................36
INSTALLATION.........................36
CABLE TENSIONER
ADJUSTMENTS
ADJUSTMENT........................37
RELEASE HANDLE
REMOVAL.............................38
INSTALLATION.........................38
BRAKES - BASE
DIAGNOSIS AND TESTING - BASE BRAKE
SYSTEM
Base brake components consist of the brake shoes,
calipers, wheel cylinders, brake drums, rotors, brake
lines, master cylinder, booster, and parking brake
components.
Brake diagnosis involves determining if the prob-
lem is related to a mechanical, hydraulic, or vacuum
operated component.
The first diagnosis step is the preliminary check.
PRELIMINARY BRAKE CHECK
(1) Check condition of tires and wheels. Damaged
wheels and worn, damaged, or underinflated tires
can cause pull, shudder, vibration, and a condition
similar to grab.(2) If complaint was based on noise when braking,
check suspension components. Jounce front and rear
of vehicle and listen for noise that might be caused
by loose, worn or damaged suspension or steering
components.
(3) Inspect brake fluid level and condition. Note
that the brake reservoir fluid level will decrease in
proportion to normal lining wear.Also note that
brake fluid tends to darken over time. This is
normal and should not be mistaken for contam-
ination.
(a) If fluid level is abnormally low, look for evi-
dence of leaks at calipers, wheel cylinders, brake
lines, and master cylinder.
(b) If fluid appears contaminated, drain out a
sample to examine. System will have to be flushed
if fluid is separated into layers, or contains a sub-
stance other than brake fluid. The system seals
5 - 2 BRAKES - BASEDR

and cups will also have to be replaced after flush-
ing. Use clean brake fluid to flush the system.
(4) Check parking brake operation. Verify free
movement and full release of cables and pedal. Also
note if vehicle was being operated with parking
brake partially applied.
(5) Check brake pedal operation. Verify that pedal
does not bind and has adequate free play. If pedal
lacks free play, check pedal and power booster for
being loose or for bind condition. Do not road test
until condition is corrected.
(6) Check booster vacuum check valve and hose.
(7) If components checked appear OK, road test
the vehicle.
ROAD TESTING
(1) If complaint involved low brake pedal, pump
pedal and note if it comes back up to normal height.
(2) Check brake pedal response with transmission
in Neutral and engine running. Pedal should remain
firm under constant foot pressure.
(3) During road test, make normal and firm brake
stops in 25-40 mph range. Note faulty brake opera-
tion such as low pedal, hard pedal, fade, pedal pulsa-
tion, pull, grab, drag, noise, etc.
(4) Attempt to stop the vehicle with the parking
brake only and note grab, drag, noise, etc.
PEDAL FALLS AWAY
A brake pedal that falls away under steady foot
pressure is generally the result of a system leak. The
leak point could be at a brake line, fitting, hose, or
caliper/wheel cylinder. If leakage is severe, fluid will
be evident at or around the leaking component.
Internal leakage (seal by-pass) in the master cylin-
der caused by worn or damaged piston cups, may
also be the problem cause.
An internal leak in the ABS or RWAL system may
also be the problem with no physical evidence.
LOW PEDAL
If a low pedal is experienced, pump the pedal sev-
eral times. If the pedal comes back up worn linings,
rotors, drums, or rear brakes out of adjustment are
the most likely causes. The proper course of action is
to inspect and replace all worn component and make
the proper adjustments.
SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn, damaged
tires.
NOTE: Some pedal pulsation may be felt during
ABS activation.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables.
²Loose/worn wheel bearing.
²Seized caliper or wheel cylinder piston.
²Caliper binding on corroded bushings or rusted
slide surfaces.
²Loose caliper mounting.
²Drum brake shoes binding on worn/damaged
support plates.
²Mis-assembled components.
²Long booster output rod.
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
DRBRAKES - BASE 5 - 3
BRAKES - BASE (Continued)

and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Rusty caliper slide surfaces
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.
BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
mile or two. However, if the lining is both soaked and
dirt contaminated, cleaning and/or replacement will
be necessary.
BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of
leaking calipers or wheel cylinders, worn seals, driv-
ing through deep water puddles, or lining that hasbecome covered with grease and grit during repair.
Contaminated lining should be replaced to avoid fur-
ther brake problems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components
may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and
pull. A worn or damaged tire can also cause pull.
Severely worn tires with very little tread left can
produce a grab-like condition as the tire loses and
recovers traction. Flat-spotted tires can cause vibra-
tion and generate shudder during brake operation. A
tire with internal damage such as a severe bruise,
cut, or ply separation can cause pull and vibration.
BRAKE NOISES
Some brake noise is common with rear drum
brakes and on some disc brakes during the first few
stops after a vehicle has been parked overnight or
stored. This is primarily due to the formation of trace
corrosion (light rust) on metal surfaces. This light
corrosion is typically cleared from the metal surfaces
after a few brake applications causing the noise to
subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that
are wet or contaminated with brake fluid, grease, or
oil. Glazed linings and rotors with hard spots can
also contribute to squeak. Dirt and foreign material
embedded in the brake lining will also cause squeak/
squeal.
A very loud squeak or squeal is frequently a sign of
severely worn brake lining. If the lining has worn
through to the brake shoes in spots, metal-to-metal
contact occurs. If the condition is allowed to continue,
rotors and drums can become so scored that replace-
ment is necessary.
BRAKE CHATTER
Brake chatter is usually caused by loose or worn
components, or glazed/burnt lining. Rotors with hard
spots can also contribute to chatter. Additional causes
of chatter are out-of-tolerance rotors, brake lining not
securely attached to the shoes, loose wheel bearings
and contaminated brake lining.
THUMP/CLUNK NOISE
Thumping or clunk noises during braking are fre-
quentlynotcaused by brake components. In many
cases, such noises are caused by loose or damaged
steering, suspension, or engine components. However,
calipers that bind on the slide surfaces can generate
a thump or clunk noise. In addition, worn out,
improperly adjusted, or improperly assembled rear
brake shoes can also produce a thump noise.
5 - 4 BRAKES - BASEDR
BRAKES - BASE (Continued)

(6) Install outboard brake shoe in adapter.
(7) Tilt the top of the caliper over rotor and under
adapter. Then push the bottom of the caliper down
onto the adapter.(8) Install caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(9) Install wheel and tire assemblies and lower
vehicle, (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(10) Apply brakes several times to seat caliper pis-
tons and brake shoes and obtain firm pedal.
(11) Top off master cylinder fluid level.
DISC BRAKE CALIPERS
DESCRIPTION
The calipers are a single piston type in the rear
and dual piston type in the front. The calipers are
free to slide laterally, this allows continuous compen-
sation for lining wear.
Fig. 12 Inboard Brake Shoe
1 - INBOARD SHOE
2 - CALIPER ADAPTER
Fig. 13 Outboard Brake Shoe
1 - OUTBOARD SHOE
2 - CALIPER ADAPTER
Fig. 14 Top Anti-Rattle Spring
1 - CALIPER ADAPTER
2 - ANTI-RATTLE SPRING
Fig. 15 Bottom Anti-Rattle Spring
1 - ANTI-RATTLE SPRING
2 - CALIPER ADAPTER
DRBRAKES - BASE 5 - 11
BRAKE PADS/SHOES (Continued)

OPERATION
When the brakes are applied fluid pressure is
exerted against the caliper piston. The fluid pressure
is exerted equally and in all directions. This means
pressure exerted against the caliper piston and
within the caliper bore will be equal (Fig. 16).
Fluid pressure applied to the piston is transmitted
directly to the inboard brake pad. This forces the pad
lining against the inner surface of the disc brake
rotor. At the same time, fluid pressure within the pis-
ton bore forces the caliper to slide inward on the
mounting bolts. This action brings the outboard
brake pad lining into contact with the outer surface
of the disc brake rotor.
In summary, fluid pressure acting simultaneously
on both piston and caliper, produces a strong clamp-
ing action. When sufficient force is applied, friction
will attempt to stop the rotors from turning and
bring the vehicle to a stop.
Application and release of the brake pedal gener-
ates only a very slight movement of the caliper and
piston. Upon release of the pedal, the caliper and pis-
ton return to a rest position. The brake pads do not
retract an appreciable distance from the rotor. In
fact, clearance is usually at, or close to zero. The rea-
sons for this are to keep road debris from gettingbetween the rotor and lining and in wiping the rotor
surface clear each revolution.
The caliper piston seal controls the amount of pis-
ton extension needed to compensate for normal lining
wear.
During brake application, the seal is deflected out-
ward by fluid pressure and piston movement (Fig.
17). When the brakes (and fluid pressure) are
released, the seal relaxes and retracts the piston.
The amount of piston retraction is determined by
the amount of seal deflection. Generally the amount
is just enough to maintain contact between the pis-
ton and inboard brake pad.
REMOVAL
REMOVAL - REAR
(1) Install prop rod on the brake pedal to keep
pressure on the brake system.
(2) Raise and support vehicle.
(3) Remove the wheel and tire assembly.
(4) Drain small amount of fluid from master cylin-
der brake reservoir with suction gun.
(5) Remove the brake hose banjo bolt if replacing
caliper (Fig. 18).
(6) Remove the caliper mounting slide pin bolts
(Fig. 18).
(7) Remove the caliper from vehicle.
REMOVAL - FRONT
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose with result. Provide a suitable support to hang
the caliper securely.
(1) Install prop rod on the brake pedal to keep
pressure on the brake system.
Fig. 16 Brake Caliper Operation
1 - CALIPER
2 - PISTON
3 - PISTON BORE
4 - SEAL
5 - INBOARD SHOE
6 - OUTBOARD SHOE
Fig. 17 Lining Wear Compensation By Piston Seal
1 - PISTON
2 - CYLINDER BORE
3 - PISTON SEAL BRAKE PRESSURE OFF
4 - CALIPER HOUSING
5 - DUST BOOT
6 - PISTON SEAL BRAKE PRESSURE ON
5 - 12 BRAKES - BASEDR
DISC BRAKE CALIPERS (Continued)