NHTSA ID Number: 10245447
Manufacturer Communication Number: L-SB-0032-23 Rev
TSB/Document Date: 2023-11-27
Summary
TSB: Some 2016 ? 2022 model year RX 450h and 2018 ? 2022 model year RX 450hL vehicles may exhibit a squawk/knock noise from the engine compartment when depressing and/or releasing the brake pedal. Follow the Repair Procedure in this bulletin to address this condition.
1
Brake Booster Pump Connector
Figure 3.
1
1
1
1
1
Tape Covering Brake Booster
Pump Connectors
1
Tape Covering Brake Booster
Pump Connectors
© 2023 Lexus
, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 9 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
B. Perform the accumulator pressure zero down.
NOTE
Using GTS+ to perform accumulator pressure zero down causes the pressurized brake fluid in
the accumulator to be returned to the brake master cylinder reservoir assembly.
(1) Drain the brake fluid in the brake master cylinder reservoir assembly to near the
MIN line.
(2) Connect Techstream to the DLC3 with the power switch OFF.
(3) Check that the parking brake is applied and turn the power switch to IG-ON.
(4) Turn GTS+ ON and select the following: Chassis – ABS/VSC/TRAC –
Utility / ECB (Electronically Controlled Brake System) Utility – Zero Down.
(5) When the buzzer sounds, turn the power switch to IG-OFF.
(6) Turn Techstream OFF and disconnect Techstream from the DLC3.
C. Separate the No. 1 reservoir hose.
(1) Slide the clip and disconnect the No. 1
reservoir hose from the reservoir tube.
Figure 4.
NOTE
Do NOT disconnect the master
cylinder reservoir side of the hose.
2
1
1
No. 1 Reservoir Hose Clip
2
The No. 1 Reservoir Hose
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 10 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(2) AFTER the No.1 reservoir hose is
disconnected, quickly attach the hose
plug and the actuator plug.
Figure 5. Hose Plug Installed
CAUTION
The plugs and cap will prevent
fluid from getting onto
the vehicle.
Do NOT clamp the hose.
Clamping the hose may cause
damage to the hose which could
result in a leak.
Figure 6. Actuator Plug Installed
1
1
Actuator Plug
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 11 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
D. Remove the brake actuator assembly with bracket.
(1) Release the lock lever and disconnect
the electrical connector from the brake
actuator assembly.
Figure 7.
1
2
(2) Cover the electrical connector with tape.
1
Release the Lock Lever
2
Disconnect the Electrical Connector
Figure 8.
CAUTION
Be careful NOT to allow ANY
brake fluid to enter
the connector.
Taping the connector will
prevent fluid from contaminating
the connector.
1
1
Electrical Connector
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 12 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(3) Using a union nut wrench, disconnect
the six brake lines from the brake
actuator assembly.
Figure 9.
1
1
1
1
1
1
(4) As each line is disconnected, quickly
attach each bleeder plug cap.
1
Figure 10.
CAUTION
This will help prevent air from
entering the system.
1
1
Cap Attached to Disconnected Line
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 13 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(5) Using a union nut wrench, separate the
No. 1 brake actuator tube from the
brake actuator assembly.
Figure 11.
CAUTION
Do NOT remove the brake
actuator tube from the brake
booster pump assembly ONLY
remove this from the brake
actuator assembly.
This will help prevent air from
entering the system.
If the line is removed completely,
you MUST pre-fill the tube with
brake fluid BEFORE re-installing.
Do NOT kink or damage the
No. 1 brake actuator tube.
Do NOT allow ANY foreign matter
such as dirt or dust to enter the
No. 1 brake actuator tube from
the connecting parts.
(6) As each line is disconnected from the
brake actuator assembly, quickly attach
each cap.
1
1
Point of Separation
Figure 12.
1
CAUTION
This will help prevent air from
entering the system.
1
Attach Cap Here
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 14 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(7) Remove the bolt and No. 1 brake tube clamp to separate the No. 1 brake actuator tube
from the No. 1 brake actuator bracket.
(8) Remove the bolt, nut, and No. 1 brake actuator bracket.
(9) Remove the brake actuator bracket spacer and brake actuator bracket cushion from
the No. 1 brake actuator bracket assembly.
(10) Remove the two nuts and brake actuator assembly with bracket.
CAUTION
Do NOT kink or damage the brake lines.
Do NOT hold the brake actuator assembly with bracket by the connector, hose,
or union.
Do NOT allow ANY foreign matter such as dirt or dust to enter the brake lines from
the connecting parts.
Remove the brake actuator assembly with bracket while avoiding the brake lines.
10. Install the NEW brake actuator assembly.
A. Install the brake actuator assembly to the brake actuator bracket.
(1) Install the two brake actuator bracket cushions and two brake actuator bracket
spacers to the brake actuator bracket assembly.
(2) Install the brake actuator assembly to the brake actuator bracket assembly with the
three bolts.
Torque: 9.3 N*m (95 kgf*cm, 82 in*lbf)
B. Install the brake actuator with the bracket.
(1) Install the brake actuator with bracket with the two nuts.
Torque: 8.0 N*m (82 kgf*cm, 71 in*lbf)
CAUTION
Do NOT kink or damage the brake lines.
Do NOT hold the brake actuator with bracket by the connector, hose, or union.
Do NOT allow any foreign matter such as dirt or dust to enter the brake lines from
the connecting parts.
Do NOT drop the brake actuator assembly. Do NOT use parts that have
been dropped.
Install the brake actuator with bracket while avoiding the brake lines.
(2) Install the brake actuator bracket cushion and brake actuator bracket spacer to the
No. 1 brake actuator bracket.
(3) Install the No. 1 brake actuator bracket assembly with the bolt and nut.
Torque:
Bolt: 19 N*m (194 kgf*cm, 14 ft*lbf)
Nut: 8.0 N*m (82 kgf*cm, 71 in*lbf)
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 15 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(4) Remove the cap from the No. 1 brake
actuator tube and quickly install it to the
brake actuator assembly.
Figure 13.
CAUTION
This will help prevent air from
entering the system.
The No. 1 brake actuator tube
should NOT have been removed
from the brake booster
pump assembly.
If the No. 1 brake actuator tube
was removed from the brake
booster pump assembly and the
actuator, it must be pre-filled
before re-installing to prevent air
from entering the system.
1
1
Remove Cap Here
(5) Install the No. 1 brake tube clamp with the bolt to secure the No. 1 brake actuator tube to
the No. 1 brake actuator bracket.
(6) Using a union nut wrench, fully tighten
the No. 1 brake actuator tube.
Figure 14.
Torque: 15.2 N*m (155 kgf*cm, 11 ft*lbf)
CAUTION
Do NOT kink or damage the No. 1
brake actuator tube.
Do NOT allow the No. 1 brake
actuator tube to twist or interfere
with other parts or the vehicle
body during tightening.
Do NOT allow any foreign matter
such as dirt or dust to enter the
No. 1 brake actuator tube from
the connecting parts.
Calculate the torque wrench
reading when changing the
fulcrum length of the torque
wrench. Refer to the applicable
Repair Manual.
When using a union nut wrench
(fulcrum length of 22 mm [0.866
in.]) + torque wrench (fulcrum
length of 162 mm [6.38 in.]):
13.38 N*m (136 kgf*cm, 10 ft*lbf).
2
1
1
Torque Wrench Fulcrum Length
2
Union Nut Wrench
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 16 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(7)
Fully tighten the bolt.
Torque: 7.0 N*m (71 kgf*cm, 62 in*lbf)
(8)
Install the nut to secure the connector box.
Torque: 8.0 N*m (82 kgf*cm, 71 in*lbf)
(9) Install the brake tube clamp to the vehicle body with the bolt.
Torque: 4.9 N*m (50 kgf*cm, 43 in*lbf)
(10)
Pre-fill the six brake actuator ports with
brake fluid before re-installing the line.
Figure 15.
CAUTION
This will help prevent air from
entering the system.
1
1
(11)
AFTER removing each cap, quickly
tighten each brake line (BEFORE
removing another cap) to the correct
position on the brake
actuator assembly.
Brake Actuator Port
Figure 16.
1
1
1
CAUTION
This will help prevent air from
entering the system.
1
1
1
© 2023 Lexus, a division of Toyota Motor Sales, USA
1
L-SB-0032-23
Rev1
May 15, 2023
Page 17 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(12)
Using a union nut wrench, fully tighten
each brake line.
Figure 17.
Torque: 15.2 N*m (155 kgf*cm, 11 ft*lbf)
1
1
CAUTION
Do NOT kink or damage the
brake lines.
Do NOT allow the brake lines to
twist or interfere with other parts
or the vehicle body
during tightening.
Do NOT allow any foreign matter
such as dirt or dust to enter the
brake lines from the
connecting parts.
Calculate the torque wrench
reading when changing the
fulcrum length of the torque
wrench. Refer to the applicable
Repair Manual.
When using a union nut wrench
(fulcrum length of 22 mm [0.866
in.]) + torque wrench (fulcrum
length of 162 mm [6.38 in.]):
13.38 N*m (136 kgf*cm, 10 ft*lbf)
(13)
Remove the tape and connect the
connector to the brake actuator
assembly and lock the lock lever.
1
1
1
1
3
2
1
2
Torque Wrench Fulcrum Length
3
Union Nut Wrench
Figure 18.
1
CAUTION
- Mixes well with conventional fluids
- Low-moisture formula provides excellent vapor lock...
- Ideal for hydraulic and disc brakes
- Provides an extra margin of safety in extreme braking...
- Mix of polyglycol ethers ensures hot brake-system operation...
- Excellent for ABS, disc and drum brake systems
- Delivers braking power when needed by avoiding a spongy...
- Both wet and dry boiling points exceed the minimum...
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TSB/Document ID: L-SB-0032-23 Rev
Replacement Service Bulletin Number:
MFR Communication Date: 2023-10-02
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE AND ENGINE COOLING
MFR Component System:
MFR Component Subsystem:
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