Toyota Avalon (XX50): Brake System(for Hv Model)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Brake / Brake System (other) / Brake System(for Hv Model)

On-vehicle Inspection

ON-VEHICLE INSPECTION

CAUTION / NOTICE / HINT

NOTICE:

DTCs may be stored during the inspection procedure. Be sure to clear the DTCs and check that no DTCs are output after the inspection is finished.

PROCEDURE

1. INSPECT PRESSURE SENSOR

(a) Check auxiliary battery voltage.

Standard Voltage:

11 to 14 V (while the power switch is off)

(b) Set a pedal effort gauge and SST, and connect the Techstream.

(1) Set a pedal effort gauge and SST.

SST: 09709-29018

09709-00060

*a	Pedal Effort Gauge
*b	SST (LSPV Gauge)
*c	SST (No. 1 Nipple)

(2) Connect the Techstream to the DLC3 with the power switch off, the shift lever in P and the parking brake applied.

(3) Turn the power switch on (IG) and turn the Techstream on.

(4) Bleed air from SST (LSPV gauge).

Click here

(1) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List / Reaction Force Pressure and Servo Pressure.

Chassis > ABS/VSC/TRAC > Data List

Tester Display
Reaction Force Pressure
Servo Pressure

(2) Check the value output from "Reaction Force Pressure" and "Servo Pressure" by depressing the brake pedal.

Standard Result:

Pedal Effort	Reaction Force Pressure (MPa)	Servo Pressure (MPa)	Front Right Wheel Hydraulic Pressure	Rear Left Wheel Hydraulic Pressure
50 N (5 kgf, 11.2 lbf)	0.04 to 0.84	3.42 to 4.02	1.42 to 5.42 MPa (14.4 to 55.2 kgf/cm2, 206 to 786 psi)	1.42 to 5.42 kPa (14.4 to 55.2 kgf/cm2, 206 to 786 psi)
100 N (10 kgf, 22.5 lbf)	0.66 to 1.46	5.98 to 6.58	3.98 to 7.98 MPa (40.5 to 81.3 kgf/cm2, 577 to 1157 psi)	3.98 to 7.98 kPa (40.5 to 81.3 kgf/cm2, 577 to 1157 psi)
150 N (15 kgf, 33.7 lbf)	1.28 to 2.08	8.55 to 9.15	6.55 to 10.55 MPa (66.8 to 107.5 kgf/cm2, 950 to 1530 psi)	6.55 to 10.55 kPa (66.8 to 107.5 kgf/cm2, 950 to 1530 psi)
200 N (20 kgf, 45.0 lbf)	1.90 to 2.70	10.57 to 11.17	8.57 to 10.8 MPa (87.5 to 110.2 kgf/cm2, 1243 to 1566 psi)	8.57 to 10.8 kPa (87.5 to 110.2 kgf/cm2, 1243 to 1566 psi)

Standard Result:

Pedal Effort	Reaction Force Pressure (MPa)	Servo Pressure (MPa)	Front Left Wheel Hydraulic Pressure	Rear Right Wheel Hydraulic Pressure
50 N (5 kgf, 11.2 lbf)	0.04 to 0.84	3.42 to 4.02	1.42 to 5.42 kPa (14.4 to 55.2 kgf/cm2, 206 to 786 psi)	1.42 to 5.42 kPa (14.4 to 55.2 kgf/cm2, 206 to 786 psi)
100 N (10 kgf, 22.5 lbf)	0.66 to 1.46	5.98 to 6.58	3.98 to 7.98 MPa (40.5 to 81.3 kgf/cm2, 577 to 1157 psi)	3.98 to 7.98 kPa (40.5 to 81.3 kgf/cm2, 577 to 1157 psi)
150 N (15 kgf, 33.7 lbf)	1.28 to 2.08	8.55 to 9.15	6.55 to 10.55 MPa (66.8 to 107.5 kgf/cm2, 950 to 1530 psi)	6.55 to 10.55 kPa (66.8 to 107.5 kgf/cm2, 950 to 1530 psi)
200 N (20 kgf, 45.0 lbf)	1.90 to 2.70	10.57 to 11.17	8.57 to 10.8 MPa (87.5 to 110.2 kgf/cm2, 1243 to 1566 psi)	8.57 to 10.8 kPa (87.5 to 110.2 kgf/cm2, 1243 to 1566 psi)

(d) Remove the pedal effort gauge and SST.

(1) Remove the pedal effort gauge and SST, and bleed the brake line.

Click here

(e) Inspect the accumulator pressure.

(1) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List / Accumulator Pressure and MT Voltage Value.

Chassis > ABS/VSC/TRAC > Data List

Tester Display
MT Voltage Value
Accumulator Pressure

(2) While fully depressing the brake pedal 4 or 5 times, check that the MT voltage value is 10 V or more once or more.

HINT:

Usually the MT voltage value is 0 V.

(3) After confirming that the booster pump motor stops, check the accumulator pressure.

Standard Result:

15 to 21 MPa

2. INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

(a) Check auxiliary battery voltage.

Standard Voltage:

11 to 14 V (while the power switch is off)

(b) Set a pedal effort gauge and SST, and connect the Techstream.

(1) Set a pedal effort gauge and SST.

SST: 09709-29018

09709-00060

*a	Pedal Effort Gauge
*b	SST (LSPV Gauge)
*c	SST (No. 1 Nipple)

(2) Connect the Techstream to the DLC3 with the power switch off, the shift lever in P and the parking brake applied.

(3) Turn the power switch on (IG) and turn the Techstream on.

(4) Clear the DTCs.

Click here

(5) Bleed air from SST (LSPV gauge).

Click here

(1) Inspect and adjust the brake pedal height.

Click here

(2) Adjust the brake fluid level of the reservoir so that it is between the MIN line and fluid level support line.

*a	Fluid Level Support Line
*b	MIN Line

(3) Turn the Techstream on and enter the following menus: Chassis / ABS/VSC/TRAC / Utility / ECB (Electronically Controlled Brake system) Utility.

Chassis > ABS/VSC/TRAC > Utility

Tester Display
ECB Utility

(4) Select "Motor Invalid" on the "ECB (Electronically Controlled Brake system) Utility" screen.

(5) Perform "Motor Invalid" according to the display on the Techstream.

(6) Depress the brake pedal 40 times or more to return all the fluid in the accumulator back to the reservoir.

HINT:

A buzzer may sound due to low accumulator pressure. As this is not a malfunction, continue the procedure.

(7) Check that the brake pedal is firm.

(8) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List / Stroke Sensor and Stroke Sensor 2.

Chassis > ABS/VSC/TRAC > Data List

Tester Display
Stroke Sensor
Stroke Sensor2

(9) Check the values output from "Stroke Sensor" and "Stroke Sensor 2" by depressing the brake pedal.

Standard Result:

Pedal Effort	Stroke Sensor (V)	Stroke Sensor 2 (V)	Front Right Wheel Hydraulic Pressure	Rear Left Wheel Hydraulic Pressure
200 N (20 kgf, 45.0 lbf)	1.52 to 2.22	2.78 to 3.48	0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)	0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)
500 N (51 kgf, 112.4 lbf)	1.81 to 2.51	2.49 to 3.19	2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)	2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)

Pedal Effort

Stroke Sensor

(V)

Stroke Sensor 2

(V)

Front Right Wheel Hydraulic Pressure

Rear Left Wheel Hydraulic Pressure

200 N (20 kgf, 45.0 lbf)

1.52 to 2.22

2.78 to 3.48

0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)

500 N (51 kgf, 112.4 lbf)

1.81 to 2.51

2.49 to 3.19

2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)

Standard Result:

Pedal Effort	Stroke Sensor (V)	Stroke Sensor 2 (V)	Front Left Wheel Hydraulic Pressure	Rear Right Wheel Hydraulic Pressure
200 N (20 kgf, 45.0 lbf)	1.52 to 2.22	2.78 to 3.48	0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)	0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)
500 N (51 kgf, 112.4 lbf)	1.81 to 2.51	2.49 to 3.19	2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)	2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)

Pedal Effort

Stroke Sensor

(V)

Stroke Sensor 2

(V)

Front Left Wheel Hydraulic Pressure

Rear Right Wheel Hydraulic Pressure

200 N (20 kgf, 45.0 lbf)

1.52 to 2.22

2.78 to 3.48

0.04 to 2.04 MPa (0.36 to 20.76 kgf/cm2, 6 to 296 psi)

500 N (51 kgf, 112.4 lbf)

1.81 to 2.51

2.49 to 3.19

2.06 to 4.06 MPa (21.0 to 41.4 kgf/cm2, 299 to 589 psi)

(10) Remove the pedal effort gauge and SST, and bleed the brake system.

Click here

(11) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List / Accumulator Pressure, and check the output pressure.

Chassis > ABS/VSC/TRAC > Data List

Tester Display
Accumulator Pressure

Standard Result:

15 to 21 MPa

(12) Clear the DTCs.

Click here

3. INSPECT STROKE SIMULATOR

(a) Check auxiliary battery voltage.

Standard Voltage:

11 to 14 V (while the power switch is off)

(b) Connect the Techstream and set a pedal effort gauge.

(1) Set a pedal effort gauge.

(2) Connect the Techstream to the DLC3 with the power switch off, the shift lever in P and the parking brake applied.

(3) Turn the power switch on (IG) and turn the Techstream on.

(4) Clear the DTCs.

Click here

(1) Turn the power switch on (IG).

(2) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List / Stroke Sensor and Stroke Sensor 2.

Chassis > ABS/VSC/TRAC > Data List

Tester Display
Stroke Sensor
Stroke Sensor2

(3) Depress the brake pedal 4 or 5 times.

(4) Check the values output from "Stroke Sensor" and "Stroke Sensor 2" by depressing the brake pedal.

Standard Voltage:

Pedal Effort	Stroke Sensor (V)	Stroke Sensor 2 (V)
50 N (5 kgf, 11.2 lbf)	1.33 to 2.03	2.97 to 3.67
100 N (10 kgf, 22.5 lbf)	1.51 to 2.21	2.79 to 3.49
150 N (15 kgf, 33.7 lbf)	1.63 to 2.33	2.67 to 3.37

Pedal Effort

Stroke Sensor

(V)

Stroke Sensor 2

(V)

50 N (5 kgf, 11.2 lbf)

1.33 to 2.03

2.97 to 3.67

100 N (10 kgf, 22.5 lbf)

1.51 to 2.21

2.79 to 3.49

150 N (15 kgf, 33.7 lbf)

1.63 to 2.33

2.67 to 3.37

Precaution

PRECAUTION

CAUTION:

While the auxiliary battery is connected, even if the power switch is off, the brake control system activates when the brake pedal is depressed or the door courtesy switch is turned on. Therefore during servicing of the brake system components, do not depress the brake pedal or open/close the doors while the auxiliary battery is connected.

NOTICE:

This vehicle is equipped with an SRS (Supplemental Restraint System). Failure to carry out service operations in the correct sequence could cause the SRS to unexpectedly deploy during servicing. This may cause a serious accident. Before servicing (including inspection, replacement, removal, and installation of parts), be sure to read the precautionary notices for the Supplemental Restraint System.
Click here
Care must be taken to replace each part properly as it could affect the performance of the brake system and result in a driving hazard. Replace the parts with those having the same part number or equivalent.
It is very important to keep parts and the area clean when repairing the brake system.
If the vehicle is equipped with a mobile communication system, refer to Precaution in the Introduction section.
Click here
Care must be taken when using magnets as they could affect the performance of the speed sensors.
Make sure to disable brake control before disconnecting the brake lines.

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Symptom	Suspected Area	Link
Low or spongy pedal	Fluid leaks in brake system	-
	Air in brake system
	Front brake piston seals (worn or damaged)
	Rear brake piston seals (worn or damaged)
	Brake booster with master cylinder assembly (faulty)
	Parking brake actuator O-ring
Brake drag	Brake pedal free play (insufficient)
	Parking brake actuator
	Front brake pad (cracked or distorted)
	Rear brake pad (cracked or distorted)
	Front brake piston (stuck)
	Rear brake piston (stuck)
	Front brake piston (seized)
	Rear brake piston (seized)
	Brake booster with master cylinder assembly (faulty)
Brake pull	Front brake piston (stuck)
	Rear brake piston (stuck)
	Front brake pad (oily)
	Rear brake pad (oily)
	Front brake piston (seized)
	Rear brake piston (seized)
	Front disc (scored)
	Rear disc (scored)
	Front brake pad (cracked or distorted)
	Rear brake pad (cracked or distorted)
Hard pedal but brake inefficient	Front brake pad (worn)
	Rear brake pad (worn)
	Front brake pad (cracked or distorted)
	Rear brake pad (cracked or distorted)
	Front brake pad (oily)
	Rear brake pad (oily)
	Front brake pad (glazed)
	Rear brake pad (glazed)
	Front brake piston (stuck)
	Rear brake piston (stuck)
	Front brake piston (seized)
	Rear brake piston (seized)
	Front disc (scored)
	Rear disc (scored)
Noise from brakes	Front brake pad (cracked or distorted)
	Rear brake pad (cracked or distorted)
	Front brake cylinder mounting bolt (loose)
	Rear brake cylinder mounting bolt (loose)
	Front disc (scored)
	Rear disc (scored)
	Front brake pad support plate (loose)
	Rear brake pad support plate (loose)
	Front disc brake cylinder slide pin (worn)
	Rear disc brake cylinder slide pin (worn)
	Front brake pad (dirty)
	Rear brake pad (dirty)
	Front brake pad (glazed)
	Rear brake pad (glazed)
	Front brake anti-squeal shim (damaged)
	Rear brake anti-squeal shim (damaged)

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