engine MERCEDES-BENZ SPRINTER 2005 Service User Guide

MAINTENANCE - WITH ASSYST MAINTENANCE
COMPUTER
ASSYST provides information on the best possible
timing for maintenance work.
NOTE: The engine manufacturer strongly recom-
mends the use of synthetic engine oils, such as
TMobil 1 SAE 0W-40.
When the next maintenance service is due, this
will be indicated in the multi-function display with
the wrench icon symbol displayed in km/miles or
days.
²One wrench icon showing indicates Oil Service
is necessary.
²Two wrench icons showing indicates Mainte-
nance Service is necessary ± displayed in km/miles or
days.
If the display shows the number of days, a clock
symbol will also appear in the multi-function display.
You should have the maintenance performed
within the stated period/distance.
The service indicator should be reset after an oil
service and/or maintenance service has been per-
formed.
REGULAR CHECK-UPS
To maintain the safe operation of the vehicle, it is
recommended that the following tasks be performed
on a regular basis (i.e. weekly or whenever the vehi-
cle is refueled). Check:
²Engine oil level
²Brake system, clutch mechanism ± fluid level
²Battery ± acid level
²Windshield washer system and headlamp clean-
ing system ± fluid level
²Mechanical assemblies (e. g. engine, transmis-
sion, etc.) ± check for leaks
²Condition of tires and tires pressures
²All exterior lights
SPECIAL MAINTENANCE REQUIREMENTS
If bodies built by manufacturers other than
DaimlerChrysler Corporation are fitted to the vehi-
cle, the maintenance requirements and lubrication
intervals specified by the body manufacturer must be
adhered to, in addition to all standard maintenance
requirements.
Brake Fluid
Only use brake fluids approved by the manufac-
turer (DOT 4 plus).
Coolant
Corrosion inhibitor/antifreeze concentration in the
coolant should be checked before the onset of winter
(once year in countries with high prevailing temper-
atures).Replace the coolant every five years or 100,000
miles.
Dust Filter for Heating/Ventilation Replace-
ment
The dust filter and the tailgate interior filter are to
be renewed during routine maintenance service. If
operating conditions are dusty, these filters should be
renewed more frequently.
ENGINE OIL CHANGE AND FILTER REPLACEMENT
At the minimum, change the engine oil and oil fil-
ter once a year ± even if the vehicle mileage per year
is extremely low. For standard oil service schedules
refer to the chapter oil service and maintenance ser-
vice.
Once a Year
Select the viscosity of the engine oil (SAE classes)
according to the outside air temperature.
Only use engine oil approved by DaimlerChrysler
Corporation if following the ASSYST system guide-
lines.
If the fuel used has a sulphur content exceeding
0.05% by weight, the service intervals should be split
in half.
SCOPE OF WORK FOR MAINTENANCE SERVICE
Oil Service
²Engine:
Oil change and filter replacement
Check fluid levels of the following system,
refill as necessary.
²If fluid is lost, trace and eliminate cause ± as a
separate order.
²Power-assisted steering
Lubrication work:
²Trailer tow hitch (original equipment)
Maintenance
²ASSYST maintenance computer reset
Function check
²Signalling system, warning and indicator lamps
²Headlamps, exterior lighting
²Windshield wipers, windshield washer system
Check for leaks and damage.
²Check for abrasion points and ensure that lines
are correctly routed!
²All lines and hoses, sensor cables
²Rubber boots on front axle drive shafts, rubber
boots on front axle suspension ball joints, shock
absorbers
Check fluid levels for the following systems,
correct as necessary.
NOTE: Should there be a loss of fluid which cannot
be explained by regular use, trace and eliminate the
cause.
0 - 8 LUBRICATION & MAINTENANCEVA
MAINTENANCE SCHEDULES (Continued)

²Engine cooling system. Check corrosion inhibi-
tor/antifreeze, refill as necessary.
²Hydraulic brake system
²Battery
²Windshield washer system
Engine
²Fuel filter renewal
²Air cleaner with maintenance indicator:
²Check degree of contamination.
²Air cleaner filter element renewed as necessary.
Chassis and body
²Trailer coupling:
Check operation, play and retaining fixtures
²Secondary rubber springs:
Visual check
²Tire pressures:
Correct as necessary, including spare tire
²Check thickness of brake pads
²Brake test
²Check condition of steering mechanism
²Heating/ventilation dust filter renewal
ADDITIONAL MAINTENANCE WORK
Automatic transmission once only at 80,000
miles/128000 km
Oil and filter change
During every second maintenance service
Air cleaner without maintenance indicator:
Air cleaner filter element renewal
Check poly-V-belt for wear and signs of damage
During every 6th maintenance service
Rear axle
ADDITIONAL MAINTENANCE WORK AFTER YEARS
Every 3 years
Air cleaner filter element renewal (note installa-
tion date)
Every 5 years or 100,000 miles
Coolant renewal
Note coolant composition
INTERNATIONAL SYMBOLS
DESCRIPTION
DaimlerChrysler Corporation uses international
symbols to identify engine compartment lubricant
and fluid inspection and fill locations (Fig. 3).
Fig. 3 INTERNATIONAL SYMBOLS
VALUBRICATION & MAINTENANCE 0 - 9
MAINTENANCE SCHEDULES (Continued)

NOTE: In order to remove tension from the strut,
Raise the lower control arm approximately 10 mm
with a jack.
(2) Install the lower ball joint into the steering
knuckle. Tighten to 280 N´m (206 ft. lbs.).
(3) Install the strut bolts to the steering knuckle
(Fig. 8). Tighten to 185 N´m (136 ft. lbs.).
(4) Install the stop plate (Refer to 2 - SUSPEN-
SION/FRONT/SPRING STOP PLATES - INSTALLA-
TION).
(5) Lower the lower control arm.
(6) Attach the tie rod to the steering knuckle (Fig.
8). Tighten the nut to 130 N´m (96 ft. lbs.)
(7) Install the disc brake caliper adapter (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION)
(Fig. 8).
(8) Install the front tire & wheel assembly (Refer
to 22 - TIRES/WHEELS/WHEELS - INSTALLA-
TION).
(9) Lower the vehicle.
(10) Remove the spring blocks between the spring
and the spring clamp plates, While the vehicles
wheels are on the ground.
(11) Roll the vehicle approximately 1 mm forwards
and the backwards, and rock firmly.(12) Tighten the lower control arm nuts and bolts
to the frame to 150 N´m (110 ft. lbs.) (Fig. 8).
(13) Apply brake to actuate brake pressure.
SPRING
REMOVAL
(1)To do this next step the vehicle must be
on the ground.Remove the front and rear bolts on
the left and right spring clamp plates (Fig. 9).
(2) Raise and support the vehicle.
(3) Remove the front wheels.
(4) Remove the brake caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - REMOVAL).Do not
allow the caliper to hang by the hose, support
the caliper accordingly.
(5) Remove the ABS sensor from the mounting
bore in the steering knuckle (Fig. 9).
(6) Remove the outer tie rod retaining nut and
separate the tie rod from the knuckle (Fig. 9) using
special tool C-3894±A.
NOTE: In order to remove tension from the strut,
Raise the lower control arm approximately 10 mm
with a jack.
(7) Remove the strut bolts from the steering
knuckle.
(8) Remove both stop plate bolts and rotate the
plates upwards with the stabilizer link attached.
(9) Lower the lower control arm.
(10) Remove the lower ball joint nut from the
steering knuckle.
(11) Separate the lower ball joint from the knuckle
using special tool 9282.
(12) Remove the lower control arm nuts and bolts
from the frame.
(13) Remove the lower control arm from the frame
(Fig. 9).
NOTE: To avoid damaging the transverse leaf
spring, cushion the pad on the jack accordingly.
(14) Support the transverse leaf spring in the cen-
ter with a jack.
(15) Remove the left and right spring clamp plates
(Refer to 2 - SUSPENSION/FRONT/SPRING CLAMP
PLATES - REMOVAL) (Fig. 9).
NOTE: The upper spring blocks between the engine
cradle and the spring are color coded, Make sure
not to mix the blocks per sides. The blocks are dif-
ferent in sizes to accommodate the weight of the
vehicle and driver in order for the vehicle to sit
level.
Fig. 8 LOWER CONTROL ARM
1 - STRUT
2 - LOWER CONTROL ARM BOLT
3 - STOP PLATE BOLT
4 - STOP PLATE
5 - CALIPER ADPTER BOLT
6 - DISC BRAKE CALIPER
7 - LOCKING BOLT
8 - DISC BRAKE ROTOR
9 - OUTER TIE ROD END RETAINING NUT
10 - OUTER TIE ROD END
11 - LOWER BALL JOINT NUT
12 - LOWER BALL JOINT
13 - LOWER CONTROL ARM NUTS
14 - STRUT BOLT
VAFRONT 2 - 7
LOWER CONTROL ARM (Continued)

(16) Lower the jack and remove the transverse leaf
spring towards the side.
INSTALLATION
NOTE: To avoid damaging the transverse leaf
spring, cushion the pad on the jack accordingly.
NOTE: Hand tighten all bolts until vehicle is on the
ground, unless the bushings may become distorted.
NOTE: The height blocks between the engine cradle
and the spring are color coded, Make sure not to
mix the blocks per sides. The blocks are different in
sizes to accommodate the weight of the vehicle and
driver in order for the vehicle to sit level.
(1) Install the transverse leaf spring in the center
with a jack with all the rubber mounts attached.
(2) Install the lower control arm to the frame (Fig.
9).
(3) Install the knuckle on the lower ball joint.(4) Raise the lower control arm approximately 10
mm with a jack.
(5) Install both stop plate bolts to the lower control
arm
(6) Install the strut bolts to the steering knuckle.
(7) Reinstall the tie rod to the steering knuckle
(Fig. 9). Tighten to 150 N´m (110 ft. lbs.).
(8) Install the ABS sensor all the way into the
steering knuckle, the sensor will adjust automatically
when the vehicle is moved (Fig. 9).
(9) Install the disc brake caliper adapter (Fig. 9).
Tighten to 170 N´m (125 ft. lbs.).
(10) Install the front wheels.
(11) Lower the vehicle.
(12) Install the spring clamp plates (Fig. 9).
Tighten (M-10 bolts) to 65 N´m (48 ft. lbs.) (M-12
bolts) to 130 N´m (96 ft. lbs.).
(13) Roll the vehicle approximately 1 mm forwards
and the backwards, and rock firmly.
(14) Tighten the nuts on the lower control arm to
the frame to 150 N´m (110 ft. lbs.).
(15) Apply brake to actuate brake pressure.
SPRING CLAMP PLATES
REMOVAL
(1) Raise and support the vehicle.
(2) Install a jack under the lower ball joint and
lower the weight of the vehicle enough to allow a
wrench between the lower control arm and the
bracket tighten the nut.
(3) Remove the front and rear bolts to the spring
clamp plates.
(4) Remove the four inner retaining bolts and
nuts.
(5) Remove the spring clamp plate and rubber
block.
(6) Remove the shear bushings from the front and
rear bolts.
INSTALLATION
(1) Install a jack under the lower ball joint and
lower the weight of the vehicle enough to allow a
wrench between the lower control arm and the
bracket tighten the nut.
(2) Fit one spring clamp plate together with the
lower spring rubber block.
(3) Install the bolt with the shear bushing on the
rear mounting,Do not tighten yet.
(4) Install the four retaining bolts for the spring
clamp plate. Tighten to 65 N´m (48 ft.lbs.).
(5) Align the holes for the front clamp plate joint
using a suitable drift (shear bushing not installed).
(6) Remove the alignment drift.
Fig. 9 FRONT SPRING
1 - NUT
2 - STRUT
3 - STOP PLATE
4 - STOP PLATE BOLT
5 - CALIPER ADAPTER BOLT
6 - DISC BRAKE CALIPER
7 - OUTER TIE ROD END NUT
8 - ABS SENSOR
9 - SPEED SENSOR
10 - LOWER CONTROL ARM RETAINING NUTS
11 - OUTER TIE ROD END
12 - RUBBER SPRING MOUNT
13 - SHEAR BUSHING
14 - SPRING CLAMP PLATE BOLT
15 - SPRING CLAMP PLATE
16 - LOWER RUBBER SPRING MOUNT
17 - SPRING
18 - STRUT BOLTS
19 - LOWER CONTROL ARM BOLTS
2 - 8 FRONTVA
SPRING (Continued)

STANDARD PROCEDURE - TOE ADJUSTMENT
CAMBER AND CASTER ARE NOT ADJUSTABLE
(TOE ONLY)..
The wheel toe position adjustment is the final
adjustment.
(1) Start the engine and turn wheels both ways
before straightening the wheels. Secure the steering
wheel with the front wheels in the straight-ahead
position.
(2) Loosen the tie rod jam nuts.
NOTE: Each front wheel should be adjusted for
one-half of the total toe position specification. This
will ensure the steering wheel will be centered
when the wheels are positioned straight-ahead.
(3) Adjust the wheel toe position by turning the
inner tie rod as necessary.
(4) Tighten the tie rod jam nut to 50 N´m (37 ft.
lbs.).
(5) Verify the specifications
(6) Turn off engine.
SPECIFICATIONS
FRONT SPECIFICATIONS
DESCRIPTION FRONT SPECIFICATION
Toe-In  .16É
DESCRIPTION FRONT SPECIFICATION
Camber  .75É
Camber
Left to Right Difference
Max1.33É
Caster  .5É
Steering Knuckle
Inclination .5É
Steering Knuckle
Inclination
Left to Right Difference
Max1É
REAR SPECIFICATIONS
DESCRIPTION REAR SPECIFICATION
Toe-In
Max0É ( .25É)
Camber
Max0É (-.66É/+.33É)
Inclination of Rear
Wheels (Individual Wheel
Toe)= Maximum
Inclination of Rear Axle
Max0É ( .25É)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Outer Tie Rod End Jam
Nut50 37 Ð
VAWHEEL ALIGNMENT 2 - 19
WHEEL ALIGNMENT (Continued)

DIFFERENTIAL & DRIVELINE
TABLE OF CONTENTS
page page
PROPELLER SHAFT......................1REAR AXLE............................10
PROPELLER SHAFT
TABLE OF CONTENTS
page page
PROPELLER SHAFT
DIAGNOSIS AND TESTING................1
STANDARD PROCEDURE.................3
SPECIFICATIONS........................5
SPECIAL TOOLS........................5
PROPELLER SHAFT
REMOVAL.............................6INSTALLATION..........................6
CENTER BEARING
REMOVAL.............................8
INSTALLATION..........................9
PROPELLER SHAFT
DIAGNOSIS AND TESTING
PROPELLER SHAFT VIBRATION
Out-of-round tires or wheels that are out of bal-
ance, will cause a low frequency vibration.Driveline vibration can be from loose or damaged
engine mounts.
Propeller shaft vibration increases with vehicle
speed. A vibration within a specific speed is not usu-
ally caused by a out of balanced propeller shaft.
Worn universal joints or an incorrect propeller shaft
angle, usually cause such a vibration.
VADIFFERENTIAL & DRIVELINE 3 - 1

DRIVELINE VIBRATION
Drive Condition Possible Cause Correction
Propeller Shaft Noise 1) Undercoating or other foreign
material on shaft.1) Clean exterior of shaft and wash
with solvent.
2) Loose U-joint clamp screws. 2) Install new clamps and screws
and tighten to proper torque.
3) Loose or bent U-joint yoke or
excessive runout.3) Install new yoke.
4) Incorrect driveline angularity. 4) Measure and correct driveline
angles.
5) Rear spring center bolt not in
seat.5) Loosen spring u-bolts and seat
center bolt.
6) Worn U-joint bearings. 6) Install new U-joint.
7) Propeller shaft damaged or out
of balance.7) Installl new propeller shaft.
8) Broken rear spring. 8) Install new rear spring.
9) Excessive runout or unbalanced
condition.9) Re-index propeller shaft, test,
and evaluate.
10) Excessive drive pinion gear
shaft runout.10) Re-index propeller shaft and
evaluate.
11) Excessive axle yoke deflection. 11) Inspect and replace yoke if
necessary.
12) Excessive transfer case runout. 12) Inspect and repair as necessary.
Universal Joint Noise 1) Loose U-joint clamp screws. 1) Install new clamps and screws
and tighten to proper torque.
2) Lack of lubrication. 2) Replace as U-joints as
necessary.
PROPELLER SHAFT BALANCE
NOTE: Removing and indexing the propeller shaft
180É relative to the yoke may eliminate some vibra-
tions.
If propeller shaft is suspected of being out of bal-
ance, verify with the following procedure:
(1) Place vehicle in netrual.
(2) Raise and support the vehicle by the axles as
level as possible.
(3) Clean all foreign material from propeller shaft
and universal joints.
(4) Inspect propeller shaft for missing balance
weights, broken welds, and bent areas.
NOTE: If propeller shaft is bent, it must be replaced.
(5) Inspect universal joints for wear, properly
installed and correct alignment with the shaft.
(6) Check universal joint clamp screws torque.
(7) Remove wheels and tires. Install wheel lug
nuts to retain the brake drums/rotors.(8) Mark and number propeller shaft six inches
from the pinion yoke end at four positions 90É apart.
(9) Run and accelerate the vehicle until vibration
occurs. Note intensity and speed the vibration
occurred. Stop the engine.
(10) Install a screw clamp at position 1 (Fig. 1).
(11) Start engine and re-check for vibration. If lit-
tle or no change in vibration is evident, move clamp
to the next positions and repeat vibration test.
NOTE: If there is no difference in vibration at the
other positions, the vibration may not be propeller
shaft.
(12) If vibration decreased, install a second clamp
(Fig. 2) and repeat vibration test.
(13) If additional clamp causes additional vibra-
tion, separate clamps 1/2 inch above and below the
mark. Repeat the vibration test (Fig. 3).
(14) Increase distance between clamps and repeat
test until vibration is at the lowest level. Bend the
slack end of the clamps so the screws will not loosen.
3 - 2 PROPELLER SHAFTVA
PROPELLER SHAFT (Continued)

REAR AXLE
TABLE OF CONTENTS
page page
REAR AXLE
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING................10
STANDARD PROCEDURE - DRAIN AND FILL . . 11
REMOVAL.............................11
INSTALLATION.........................12
SPECIFICATIONS.......................13
SPECIAL TOOLS.......................14
AXLE SHAFTS
REMOVAL.............................15
INSTALLATION.........................15AXLE BEARINGS/SEALS
REMOVAL.............................17
INSTALLATION.........................17
AXLE SHAFTS - DUAL REAR WHEELS
REMOVAL.............................19
INSTALLATION.........................19
AXLE HUB BEARINGS/SEALS
REMOVAL.............................20
INSTALLATION.........................20
PINION SEAL
REMOVAL.............................22
INSTALLATION.........................22
REAR AXLE
DESCRIPTION
The axle housings consist of a cast iron center sec-
tion with axle tubes extending from either side. The
tubes are pressed into and welded to the differential
housing to form a one-piece axle housing. The SRW
axle has semi-floating axle shafts, DRW has full-
floating axle shafts.
NOTE: Axle seals, axle bearings, pinion seal and
differential cover are the only serviceble compo-
nents. If differential is damaged/noisy the axle must
be replaced.
OPERATION
The axle receives power from the transmission
through the rear propeller shaft. The rear propeller
shaft is connected to the pinion gear which rotates
the differential through the gear mesh with the ring
gear bolted to the differential case. The engine power
is transmitted to the axle shafts through the pinion
mate and side gears. The side gears are splined to
the axle shafts.
DIAGNOSIS AND TESTING
NOTE: Axle seals, axle bearings, pinion seals and
differential cover are the only serviceble compo-
nents. If differential is damaged/noisy the axle must
be replaced.
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearingshave a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
3 - 10 REAR AXLEVA

heard during a coast, the front pinion bearing is the
source.
Differential bearings usually produce a low pitch
noise. Differential bearing noise is similar to pinion
bearing noise. The pitch of differential bearing noise
is also constant and varies only with vehicle speed.
Axle shaft bearingsproduce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side-gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
NOTE: All driveline components should be exam-
ined before starting any repair.
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listenfor the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
STANDARD PROCEDURE - DRAIN AND FILL
NOTE: Drain oil when warm.
(1) Clean area around oil fill plug and drain plug.
(2) Remove oil drain plug and drain oil (Fig. 1).
(3) Install oil drain plug and tighten to N´m 100
(74 ft. lbs.).
(4) Remove oil fill plug and fill housing up to bot-
tom edge of oil fill hole (Fig. 1).
(5) Install oil fill plug and tighten to N´m 100 (74
ft. lbs.).
REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the axle
and secure axle to device.
(3) Remove wheels and tires.
(4) Unplug wear indicator cable (Fig. 2) and (Fig.
3).
(5) Detach cable connector for brake pad wear
indicator.
(6) Remove ABS sensor and clamp bushing from
mounting bore.
NOTE: The right-hand ABS sensor cable is labeled
at the factory with a white tag.
(7) Remove cable ties from the park brake cables.
Release connection cable of brake pad wear indicator
and ABS sensor cable up to the relay unit of the
parking brake.
(8) Remove brake cables from adjuster.
(9) Remove brake calipers with adapters and lines.
Fig. 1 FILL PLUG
1 - FILL PLUG
2 - DRAIN PLUG
VAREAR AXLE 3 - 11
REAR AXLE (Continued)

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
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 pads
²Damaged rotor
VABRAKES - BASE 5 - 3
BRAKES - BASE (Continued)