Brake Master Cylinder: Testing and Inspection
ON-VEHICLE INSPECTION1. Hydraulic brake booster operation inspection.
a. Inspect the battery positive voltage.
Battery positive voltage: 10 - 14 Volts
b. Turn the ignition switch OFF, depress the brake pedal more than 40 times.
c. Install Load Sensing Proporting Valve (LSPV) gauge Special Service Tool (SST) 09709-29018 or equivalent, and brake pedal effort gauge, bleed air.
d. When booster does not operate.
Depress the brake pedal and check fluid pressure.
At 245 N (55 lbs.)
Front brake pressure: 1,470 kPa (213 psi) or more
Rear brake pressure: 0 kPa (0 psi)
At 343 N (77 lbs.)
Front brake pressure: 2,059 kPa (299 psi) or more
Rear brake pressure: 0 kPa (0 psi)
e. When booster operate.
1) Turn the ignition switch ON and wait until the put, motor has stopped.
2) Depress the brake pedal and check fluid pressure.
At 49 N (11 lbs.)
Front brake pressure: 794 - 1,814 kPa (115 - 263 psi)
Rear brake pressure: 961 - 2,148 kPa (139 - 311 psi)
At 98 N (22 lbs.)
Front brake pressure: 3,442 - 5,011 kPa (499 - 727 psi)
Rear brake pressure: 3,923 - 5,698 kPa (569 - 826 psi)
At 147 N (33 lbs.)
Front brake pressure: 5,629 - 7,845 kPa (816 - 1,138 psi)
Rear brake pressure: 6,237 - 8,640 kPa (905 - 1,253 psi)
At 196 (44 lbs.)
Front brake pressure: 8,002 - 10,591 kPa (1,161 - 1,536 psi)
Rear brake pressure: 8,718 - 11,572 kPa (1,264 - 1,678 psi)
2. In case of using LEXUS handheld tester.
a. Inspect the battery positive voltage.
Battery positive voltage: 10 - 14 Volts
b. Turn the ignition switch OFF, depress the brake pedal more than 40 times.
c. Check that the brake pedal becomes heavy to depress. If the pedal does not become to be heavy to depress, check and replace the brake line and hydraulic brake booster.
d. Turn the ignition switch ON, check the pump motor operation noise. If the pump motor does not operate, check and replace the wire harness and pump motor.
e. Connect the LEXUS hand-held tester.
1) Connect the LEXUS hand-held tester to the DLC3.
2) Turn the ignition switch ON.
3) Select the "ACTIVE TEST" mode on the LEXUS hand-held tester.
HINT:
- Please refer to the LEXUS hand-held tester operator's manual for further details.
- To protect the solenoids, hand-held tester turns OFF automatically 2 seconds after every solenoid has been turned ON.
f. Inspect the front TRAC & VSC solenoid operation.
1) Select "SA1" and "SA2" on the LEXUS hand-held tester.
2) With "SA1" and "SA2" turned ON simultaneously with the LEXUS hand-held tester, depress the brake pedal with stable force and check that the pedal cannot be depressed. If the pedal can be depressed, replace the hydraulic brake booster.
NOTICE: When operating it continuously, set the interval of more than 20 seconds.
3) Once, release the brake pedal.
4) Turn the "SA1" and "SA2" OFF, and check that the pedal can be depressed.
HINT: To protect the solenoids, hand-held tester turns OFF automatically 2 seconds after has been turned ON.
If the pedal cannot be depressed, replace the hydraulic brake booster.
g. Inspect the front ABS solenoid operation.
1) Select "SFRH" and "SFLH" on the LEXUS handheld tester.
2) With "SFRH" and "SFLH" turned ON simultaneously with the LEXUS hand-held tester, depress the brake pedal with stable force and check that the pedal cannot be depressed. If the pedal can be depressed, replace the hydraulic brake booster.
3) Once, release the brake pedal.
4) Turn the "SFRH" and "SFLH"OFF and check that the pedal can be depressed.
HINT: To protect the solenoids, hand-held tester turns OFF automatically 2 seconds after has been turned ON.
If the pedal cannot be depressed, replace the hydraulic brake booster.
5) Once, release the brake pedal. After depressing and holding the pedal with stable force, turn the SFRH and SFRR solenoids ON simultaneously.
HINT: To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
6) When the solenoids are OFF, check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
7) Once, release the brake pedal. After depressing the pedal with stable force, turn the SFLH and SFLR solenoids ON simultaneously.
HINT: To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
8) When the solenoids are OFF, check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
h. Jack up and support the vehicle.
i. Release the parking brake pedal.
j. Inspect the rear TRAC&VSC solenoid operation.
1) Select the "SA3" and "STR" on the LEXUS handheld tester.
2) Turn the "SA3" and "STR" ON simultaneously with the LEXUS hand-held tester, and check that the rear wheels by stopping them by hand.
HINT: When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible. If the rear wheels rotate, replace the hydraulic brake booster.
3) Turn the "SA3" and "STR" OFF simultaneously, and check that the rear wheels by rotating them by hand.
HINT:
- To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
- When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible.
NOTICE: When operating it continuously, set the interval of more than 20 seconds
If the rear wheels stop, replace the hydraulic brake booster.
k. Inspect the right rear ABS solenoid.
1) Select the "SA3", "STR" and "SRRH", on the LEXUS hand-held tester.
2) Turn the "SA3", "STR" and "SRRH" ON simultaneously with the LEXUS hand-held tester, and check that the right rear wheel by rotating them by hand.
HINT:
- To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
- When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible.
- When solenoid is OFF, the wheel might stop temporarily. However if the wheel rotates again, the function works normally.
If the rear wheels stop, replace the hydraulic brake booster.
3) Turn the "SA3", "STR" and "SRRH" OFF, and check that the rear wheel by stopping them by hand.
HINT:
- To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
- When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible.
If the rear wheels rotate, replace the hydraulic brake booster.
4) Depress the pedal with stable force, then turn the "SRRH" and "SRRR" ON simultaneously.
5) When the solenoids are ON, check that the right rear wheel by rotating them by hand.
l. Inspect the left rear ABS solenoid operation.
1) Select the "SA3", "STR" and "SRLH" on the LEXUS, hand-held tester.
2) Turn the "SA3", "STR" and "SRLH" ON with LEXUS hand-held tester, and check that the left rear wheel by rotating them by hand.
HINT: When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible. If the rear wheels stop, replace the hydraulic brake booster.
3) Turn the "SA3", "STR" and "SRLH" OFF and check that the rear wheels by rotating them by hand.
HINT:
- To protect the solenoids, hand-held tester turns OFF automatically 2 seconds after has been turned ON.
- When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible.
- When solenoid is OFF, the wheel might stop temporarily. However if the wheel rotates again, the function works normally.
If the rear wheels rotate, replace the hydraulic brake booster.
4) Depress the pedal with stable force, then turn the "SRLH" and "SRLR" ON simultaneously.
HINT: To protect the solenoids, hand-held tester turns OFF automatically 2 sees. after has been turned ON.
5) When the solenoids are ON, check that the right rear wheel by rotating them by hand.
HINT: When rotating the wheel fast, the fail-safe function is activated and judgement can not be made properly. So rotate the wheel as slowly as possible.
m. Lower the vehicle.
n. Disconnect the LEXUS hand-held tester.
3. In case of using ABS actuator checker.
a. Inspect the battery positive voltage.
Battery positive voltage: 10 - 14 Volts
b. Disconnect the 2 connectors from hydraulic brake booster.
c. Connect the actuator checker (SST) to the hydraulic brake booster side wire harness via the sub-wire harness (SST), as shown.
HINT: Connect the connector with the label of "FRONT" attached to the connector of actuator checker.
d. Connect the red cable of the checker to the battery positive (+) terminal and the black cable to the negative (-) terminal.
e. Place "SHEET G" SST 09990-00240 of "FRONT" on actuator checker.
f. Turn the ignition switch OFF, depress the brake pedal more than 40 times.
g. Check that the brake pedal becomes heavy to depress.
If the pedal does not become to be heavy to depress, check and replace the brake line and hydraulic brake booster.
h. Turn the ignition switch ON, check the pump motor operation noise.
If the pump motor does not operate, check and replace the wire harness and pump motor.
i. Inspect the front TRAC & VSC solenoid operation.
1) Push and hold in the and "SA2" switch simultaneously, depress and hold the brake pedal with stable force.
NOTICE: Do not keep the "SA1" and "SA2" pushed down for more than 10 seconds. When operating it continuously, set the interval of more than 20 seconds.
2) Check that the brake pedal cannot be depressed. If the pedal can be depressed, replace the hydraulic bras_ booster.
3) Release the "SA1" switch and check that the pedal can be depressed.
If the pedal can be depressed, replace the hydraulic brake booster.
4) Release the "SA2" switch and check that the pedal can be depressed.
If the pedal can be depressed, replace the hydraulic brake booster.
j. Inspect the right front ABS solenoid operation.
1) Turn the selector switch to "RH" position.
2) Push and hold in the MAIN push switch and "SA2 switch simultaneously depress and hold the brake pedal with stable force.
NOTICE: Do not keep the MAIN push switch and "SA2" switch pushed down for more than 10 seconds. When operating it continuously, set the interval of more than 20 seconds.
3) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake booster.
4) Release the MAIN push switch and "SA2" switch simultaneously and check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
5) Release the brake pedal.
6) Depress and hold the brake pedal with stable force, push and hold MAIN push switch.
NOTICE: Do not keep the MAIN push switch pushed down for more than 10 seconds. When operating it continuously, set the interval of more than 20 seconds.
7) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake booster.
8) Release the MAIN push switch and "SA2" switch, and check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
9) Release the brake pedal.
k. Inspect the left front ABS solenoid operation.
1) Turn the selector switch to "LH" position.
2) Push and hold in the MAIN push switch and "SA1" switch simultaneously, depress and hold the brake pedal with stable force.
NOTICE: Do not keep the MAIN push switch and "SA1" switch pushed down for more than 10 seconds. When operating it continuously, set the interval of more than 20 seconds.
3) Check that the brake pedal cannot be depressed. if the pedal can be depressed, replace the hydraulic brake booster.
4) Release the MAIN push switch and "SA1" switch simultaneously, and check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
5) Release the brake pedal.
6) Depress and hold the brake pedal with stable force, push and hold in MAIN push switch.
NOTICE: Do not keep the MAIN push switch pushed down for more than 10 seconds. When operating it continuously, set the interval of more than 20 seconds.
7) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake booster.
8) Release the MAIN push switch and "SA2" switch, and check that the pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake booster.
9) Release the brake pedal.
l. Turn the Ignition switch OFF, then reconnect the connector of sub-wire harness from the one with label of "FRONT" to "REAR".
m. Place "SHEET G" of "REAR" on the actuator checker.
n. Jack up and support the vehicle.
o. Start the engine and run it at idle.
p. Inspect the rear TRAC & VSC solenoid.
1) Release the parking brake pedal and shift the shim lever to "L'' position.
2) Push and hold the "SA3" switch and "STR" switch simultaneously.
NOTICE: Do not keep the "STR" switch pushed down for more than 10 seconds. Do not keep the "SA3" switch pushed down for more than 5 seconds. When operating it continuously, set the interval of more than 20 seconds.
3) Check that the rear wheels stop.
If the rear wheels rotate, replace the hydraulic brake booster.
4) Release the "SA3" switch and "STR" switch simultaneously.
5) Check that the rear wheels rotate.
If the rear wheels stop, replace the hydraulic brake booster.
q. Inspect the right rear ABS solenoid.
1) Turn the selector switch to "RH" position.
2) Depress the brake pedal several times the release, the pedal after the pump has begun to operate, a' wait until the pump stops.
3) Turn the ignition switch OFF.
4) With push and hold in the MAIN push switch, depress the pedal with force of 196 N (20 kgf, 44 lbs.) and hold it 6 times for 10 sees.
5) Check that pedal is not hard to depress.
If pedal is hard to depress, replace the hydraulic brake booster.
6) Start the engine and run it at idle.
7) Release the parking brake pedal and shift the shift lever to "L" position.
8) Once, release the brake pedal. After depressing the pedal with stable force, then push and hold MAIN push switch.
9) check that the right rear wheel rotate.
If the right rear wheels stop, replace the hydraulic brake booster.
r. Inspect the left rear ABS solenoid.
1) Turn the selector switch to "LH" position.
2) Depress the brake pedal several times the release the pedal after the pump has begun to operate, and wait until the pump stops.
3) Turn the ignition switch OFF.
4) With push and hold in the MAIN push switch, depress the pedal with force of 196 N (20 kgf, 44 lbs.) and hold it 6 times for 10 sees.
5) Check that pedal is not hard to depress.
If pedal is hard to depress, replace the hydraulic brake booster.
6) Start the engine and run it at idle.
7) Release the parking brake pedal and shift the shift lever to "L" position.
8) Once, release the brake pedal. After depressing the pedal with stable force, then push and hold MAIN push switch.
9) check that the left rear wheel rotate.
If the left rear wheels stop, replace the hydraulic brake booster.
s. Stop the engine and lower the vehicle.
t. Remove the "SHEET G" (SST) and disconnect the actuator checker (SST) and sub-wire harness (SST) from the hydraulic brake booster.
u. Connect the 2 connectors to the actuator.
v. Clear the DTC.