brake MITSUBISHI TRITON 1997 User Guide

BASIC BRAKE SYSTEM ± Troubleshooting35A-7
TROUBLESHOOTING35100070081
SymptomProbable causeRemedy
Vehicle pulls to one side
when brakes are applied
Grease or oil on pad or lining surfaceReplace
when brakes are a lied
Inadequate contact of pad or liningCorrect
Auto adjuster malfunctionAdjust
Drum eccentricity or uneven wearRepair or replace as necessary
Insufficient braking powerLow or deteriorated brake fluidRefill or change
Air in brake systemBleed air
Overheated brake rotor due to dragging of pad
or liningCorrect
Inadequate contact of pad or lining
Brake booster malfunction
Clogged brake line
Grease or oil on pad or lining surfaceReplace
Load sensing proportioning valve malfunction
Auto adjuster malfunctionAdjust
Increased pedal stroke
(Reducedpedal to floor
Air in brake systemBleed air
(Reduced edal to floor
board clearance)Worn lining or padReplace
Broken vacuum hose
Faulty master cylinder
Brake fluid leaksCorrect
Auto adjuster malfunctionAdjust
Excessive push rod to master cylinder
clearance
Brake dragIncomplete release of parking brakeCorrect
Clogged master cylinder return port
Incorrect parking brake adjustmentAdjust
Improper push rod to master cylinder
clearance
Faulty master cylinder piston return springReplace
Worn brake pedal return spring
Broken rear drum brake shoe to shoe spring
Lack of lubrication in sliding partsLubricate

BASIC BRAKE SYSTEM ± Troubleshooting35A-8
SymptomProbable causeRemedy
Insufficient parking brake functionWorn brake lining or padReplace
Grease or oil on lining or pad surface
Parking brake cable sticking
Stuck wheel cylinder or caliper piston
Excessive parking brake lever strokeAdjust the parking brake lever stroke or
check the parking brake cable routing
Auto adjuster malfunctionAdjust
Scraping or grinding noise when
brakes are applied
Worn brake lining or padReplace
brakes are a lied
Caliper to wheel interferenceCorrect or replace
Dust cover to disc interference
Bent brake backing plate
Cracked drums or brake disc
Squealing, groaning or chattering
noise when brakes are appliedDisc brakes ± Missing or damaged
brake pad anti-squeak shimReplace
Brake drums and linings, discs and pads
worn or scoredCorrect or replace
Improper lining parts
Disc brake ± Burred or rusted calipersCorrect or deburr
Dirty, greased, contaminated or glazed
liningsClean or replace
Drum brakes ± Weak, damaged or
incorrect shoe hold-down springs, loose
or damaged shoe hold-down pins and
springsCorrect or replace
Incorrect brake pedal or booster push rodAdjust

BASIC BRAKE SYSTEM ± Troubleshooting35A-9
SymptomProbable causeRemedy
Squealing noise
when brakes are
Bent or warped backing plate causing interference with drumReplace
when brakes are
not appliedDrum brakes ± Weak, damaged or incorrect shoe-to-shoe
spring
Poor return of brake booster, master cylinder or wheel
cylinder
Loose or extra parts in brakesRetighten
Improper positioning of pads in caliperCorrect
Improper installation of support mounting to caliper body
Improper machining of drum causing interference with
backing plate or shoeReplace drum
Disc brakes ± Rusted, stuckLubricate or replace
Worn, damaged or insufficiently lubricated wheel bearings
Incorrect brake pedal or booster push rodAdjust
Groaning, clicking or
rattling noise when
Stones or foreign material trapped inside wheel coversRemove stones, etc.
rattling noise when
brakes are not appliedLoose wheel nutsRetighten
Disc brakes ± Loose installation bolts
Worn, damaged or dry wheel bearingsLubricate or replace
Disc brakes ± Failure of shimReplace
Disc brakes ± Wear on sleeve
Incorrect brake pedal or booster push rodAdjust

35B-2
Bleeding 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Fluid Level Sensor Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Load Sensing Spring Length Check and
Adjustment Refer to GROUP 35A. . . . . . . . . . . . . . .
Load Sensing Proportioning Valve Function
Test Refer to GROUP 35A. . . . . . . . . . . . . . . . . . . . .
Disc Brake Pad Check and Replacement 23. . . . .
Front Disc Brake Rotor Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Lining Thickness Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Drum Inside Diameter Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Lining and Brake Drum Connection Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor Output Voltage Check
24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Unit Check 26. . . . . . . . . . . . . . . . . . . . . . . .
Solenoid Valve Check 27. . . . . . . . . . . . . . . . . . . . . . .
Motor Operation Check 27. . . . . . . . . . . . . . . . . . . . . . Motor Relay and Valve Relay Continuity
Check 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remedy for a Flat Battery 28. . . . . . . . . . . . . . . . . . .
BRAKE PEDAL Refer to GROUP 35A. . . . . . . .
MASTER CYLINDER AND BRAKE
BOOSTER 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOAD SENSING PROPORTIONING VALVE
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . .
FRONT DISC BRAKE 32. . . . . . . . . . . . . . . . . . . . .
REAR DRUM BRAKE
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . .
HYDRAULIC UNIT 37. . . . . . . . . . . . . . . . . . . . . . . . .
WHEEL SPEED SENSOR 39. . . . . . . . . . . . . . . . . .
ABS-ECU 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ABS <2WD> ± Troubleshooting35B-5
TROUBLESHOOTING35201110143
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection Service Points.
NOTES WITH REGARD TO DIAGNOSIS
The phenomena listed in the following table are not abnormal.
PhenomenonExplanation of phenomenon
System check soundWhen starting the engine, a thudding sound can sometimes be heard coming from inside
the engine compartment, but this is because the system operation check is being
performed, and is not an abnormality.
ABS operation sound1. Sound of the motor inside the ABS hydraulic unit operation. (whine)
2. Sound is the generated along with vibration of the brake pedal. (scraping)
3. When ABS operates, sound is generated from the vehicle chassis due to repeated
brake application and release.
(Thump: suspension; squeak: tyres)
ABS operation
(Long braking distance)For road surfaces such as snow-covered roads and gravel roads, the braking distance for
vehicles with ABS can sometimes be longer than that for other vehicles. Accordingly, advise
the customer to drive safely on such roads by lowering the vehicle speed and not being too
overconfident.
Shock during system
operation checkShock may be felt when the brake pedal is depressed slightly at a low driving speed. This
occurs due to ABS operation check (initial check at a vehicle speed of 8 km/h), and does
not indicate any malfunction.
Diagnosis detection condition can vary depending on the diagnosis code.
Make sure that checking requirements listed in the ªCommentº are satisfied when checking the trouble
symptom again.
DIAGNOSIS FUNCTION35201120108
DIAGNOSIS CODES CHECK
Read a diagnosis code by the MUT-II or ABS warning lamp.
(Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.)
ERASING DIAGNOSIS CODES
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.

ABS <2WD> ± Troubleshooting35B-14
INSPECTION CHART FOR TROUBLE SYMPTOMS35201140142
Get an understanding of the trouble symptoms and check according to the inspection procedure chart.
Trouble symptomsInspection
procedure No.Reference
page
Communication with MUT-II
is notpossible
Communication with all systems is not possible.135B-15
is not ossible.
Communication with ABS only is not possible.235B-15
When the ignition key is turned to ªONº (engine stopped), the ABS warning lamp does
not illuminate.335B-16
After the engine starts, the ABS warning lamp remains illuminated.435B-16
When the ignition key is turned to ªSTARTº, the ABS warning lamp does not illuminate.535B-17
After the ignition key is turned to ªONº, the ABS warning lamp blinks twice, and when
turned to ªSTARTº, it illuminates. When returned to ªONº, the lamp flashes once, and
then switches off.635B-17
Faulty ABS operationUnequal braking power on both sides735B-18
Insufficient braking power
ABS operates under normal braking conditions
ABS operates before vehicle stops under normal
braking conditions
Large brake pedal vibration (Caution 2.)±±
Caution
1. If steering movements are made when driving at high speed, or when driving on road surfaces
with low frictional resistance, or when passing over bumps, the ABS may operate even though
sudden braking is not being applied. Because of this, when getting information from the customer,
check if the problem occurred while driving under such conditions as these.
2. During ABS operation, the brake pedal may vibrate or may not be able to be depressed. Such
phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent
the wheels from locking and is not an abnormality.

ABS <2WD> ± Troubleshooting35B-18
Inspection Procedure 7
Brake operation is abnormal.
Probable cause
This varies depending on the driving conditions and the road surface conditions, so
problem diagnosis is difficult. However, if a normal diagnosis code is displayed, carry
out the following inspection.
Improper installation of wheel speed sensor

Incorrect sensor harness contact

Foreign material adhering to wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of rotor

Malfunction of wheel bearing

Malfunction of hydraulic unit

Malfunction of ABS-ECU
OK
Check trouble symptom.NGReplace the ABS-ECU.
OK
Check the following connector.
C-62NG
Repair
NG
Measure at ABS-ECU connector C-62.

Disconnect the connector and
measure at the harness side.

Resistance value between terminals
10-23, 7-20, 8-21 and 9-22
OK:1.2 ± 1.4 kW
(The sensor harness and connector
should be moved while these
inspections are carried out.)NG
Repair
OK
Check trouble symptom.
OK
Check the following connectors.
A-01, A-07, F-01, F-16, D-01, and C-02NG
Repair
OK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)NG
Repair
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Hydraulic unit check. (Refer to P.
35B-26.)
OK
Wheel speed sensor output voltage
check. (Refer to P. 35B-24.)NGWheel speed sensor check. (Refer to
P. 35B-39.)NGReplace the wheel speed sensor.
Wheel speed sensor installation check.NG
Repair

35C-2
For the items below, refer to GROUP
35A.
SEALANTS
ON-VEHICLE SERVICE
Brake Pedal Check and Adjustment
Stop Lamp Switch Inspection
Brake Booster Operating Test
Check Valve Operation Check
Brake Booster Vacuum Switch Check
Load Sensing Spring Length Check and
Adjustment
Load Sensing Proportioning Valve Function
Test
Front Disc Brake Rotor Check
Brake Lining Thickness Check
Brake Drum Inside Diameter Check
Brake Lining and Brake Drum Connection
Check
BRAKE PEDAL
LOAD SENSING PROPORTIONING VALVE
REAR DRUM BRAKE
For the items below, refer to GROUP
35B.
ON-VEHICLE SERVICE
Bleeding
Disc Brake Pad Check and Replacement
Wheel Speed Sensor Output Voltage Check
Hydraulic Unit Check
Solenoid Valve Check
Motor Operation Check
Motor Relay and Valve Relay Continuity Check
Remedy for a Flat Battery
MASTER CYLINDER AND BRAKE
BOOSTER
HYDRAULIC UNIT
ABS-ECU

ABS <4WD> ± Troubleshooting35C-5
TROUBLESHOOTING35101110143
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection Service Points.
NOTES WITH REGARD TO DIAGNOSIS
The phenomena listed in the following table are not abnormal.
PhenomenonExplanation of phenomenon
System check soundWhen starting the engine, a thudding sound can sometimes be heard coming from inside
the engine compartment, but this is because the system operation check is being
performed, and is not an abnormality.
ABS operation sound1. Sound of the motor inside the ABS hydraulic unit operation. (whine)
2. Sound is the generated along with vibration of the brake pedal. (scraping)
3. When ABS operates, sound is generated from the vehicle chassis due to repeated
brake application and release.
(Thump: suspension; squeak: tyres)
ABS operation
(Long braking distance)For road surfaces such as snow-covered roads and gravel roads, the braking distance for
vehicles with ABS can sometimes be longer than that for other vehicles. Accordingly, advise
the customer to drive safely on such roads by lowering the vehicle speed and not being too
overconfident.
Shock during system
operation checkShock may be felt when the brake pedal is depressed slightly at a low driving speed. This
occurs due to ABS operation check (check at a vehicle speed of 8 km/h after starting), and
does not indicate any malfunction.
Diagnosis detection condition can vary depending on the diagnosis code.
Make sure that checking requirements listed in the ªCommentº are satisfied when checking the trouble
symptom again.
DIAGNOSIS FUNCTION35201120108
DIAGNOSIS CODES CHECK
Read a diagnosis code by the MUT-II or ABS warning lamp.
(Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.)
ERASING DIAGNOSIS CODES
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.

ABS <4WD> ± Troubleshooting35C-11
DATA LIST REFERENCE TABLE35201150107
The following items can be read by the MUT-II from the ABS-ECU input data.
1. When the system is normal
Item No.Check itemChecking requirementsNormal value
11Front-right wheel speed sensorPerform a test runVehicle speeds
displayed on the12Front-left wheel speed sensor
dis layed on the
speedometer
and MUTIIare13Rear-right wheel speed sensorand MUT-II are
identical.
14Rear-left wheel speed sensor
16ABS-ECU power supply
voltageIgnition switch power supply voltage and valve
monitor voltage9 ± 16 V
25Free wheel engage switchEngage 4WDON
Engage 2WDOFF
264WD detection switchPlace the transfer lever at 4H.ON
Place the transfer lever at 2H.OFF
27Rear differential lock detection
switch
Turn on the switch.ON
switch
Turn off the switch.OFF
32G-sensor output voltageStop the vehicle.2.4 ± 2.6 V
Perform a test run.Display value
fluctuates with a
mean value of
2.5 V.
33Stop lamp switchDepress the brake pedal.ON
Release the brake pedal.OFF
2. When the ABS-ECU shut off ABS operation.
When the diagnosis system stops the ABS-ECU, the MUT-II display data will be unreliable.
ACTUATOR TEST INSPECTION TABLE35201160056
Refer to GROUP 35B ± Troubleshooting.