Lexus RX400h, Hybrid 3 2006

Bleeding the Brake System

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NOTE
This procedure requires specialized tools. Please read through the procedure and make sure you have access to the proper equipment before beginning the bleeding procedure.


CAUTION
Never bleed air from the brake hydraulic system without using the intelligent tester. failure to use the intelligent tester could cause serious injury or an accident.

Note the following before bleeding the brake system:



Move the shift lever to the P position and apply the parking brake before bleeding.
 
Add brake fluid carefully and check that the reservoir level remains between the min and max lines while bleeding the brakes.
 
Do not stand the fluid can on the reservoir inlet when bleeding the brake actuator. doing so will cause brake fluid to overflow.
 
The actuator pump motor and solenoid can be operated by the driver even if the ignition switch is off.
 
If the pump motor operates while air still remains inside the brake actuator hose, air will enter the actuator, making it more difficult to bleed the brakes. If there is concern about air remaining in the actuator hose, remove the two motor relays (skid control relay no.2) until instructed to reinstall them.
 
Although a buzzer may sound due to a decline in the accumulator pressure while bleeding, it is not necessary to stop bleeding.
 
DTCs indicating a malfunction in the motor relays (skid control relay no.2) or the pressure sensor are stored after bleeding. clear the DTCs when instructed during or after bleeding.
 

  1. Add SAE J1703 or FMVSS no. 116 DOT 3 brake fluid to the max line in the reservoir.
    CAUTION
    Add brake fluid carefully and check that the reservoir level remains between the min and max lines while bleeding the brakes. Do not stand the fluid can on the reservoir inlet when bleeding the brake actuator. Doing so will cause brake fluid to overflow.

  2.  
  3. Disable the brake control (ECB). When using the intelligent tester:
    NOTE
    When using the intelligent tester , refer to the intelligent tester operator's manual for further details. Bleed the air by following the steps displayed on the intelligent tester.

    1. Move the shift lever to the P position and apply the parking brake.
    2.  
    3. Connect the intelligent tester to the DLC3 with the ignition switch OFF as shown in the illustration.

      Click image to see an enlarged view

      Fig. Connect the intelligent tester to the DLC3 with the ignition switch OFF as shown in the illustration

    4.  
    5. Turn the ignition switch to the ON position and turn on the intelligent tester.
      NOTE
      Do not start the engine.

    6.  
    7. Enter the following menus: DIAGNOSIS / OBD/ MOBD / ABS/TRAC/VSC / ECB UTILITY / ECB INVALID.
      WARNING
      If the pump motor operates while air remains inside the brake actuator hose, air will enter the actuator, and this will make bleeding the brakes more difficult.

    8.  
    9. When removing the ABS motor relay: Remove the 2 ABS motor relays with the ignition switch off in order to disable brake control.
      WARNING
      If the pump motor operates while air remains inside the brake actuator hose, air will enter the actuator, and this will make bleeding the brakes more difficult.


      NOTE
      After the brake actuator assembly has been replaced, remove the ABS motor relay before bleeding the brakes.



      Click image to see an enlarged view

      Fig. Location of the 2 ABS motor relays

    10.  

  4.  
  5. Bleed the brake actuator hose, as follows:
    1. Connect Special Tool 09992-00242, 0992-00350 or equivalent, to the reservoir with the brake reservoir pressure adapter.

      Click image to see an enlarged view

      Fig. View of the special tools

    2.  
    3. Using Special Tool 09023-00101, loosen the bleeder plug of the actuator.
    4.  
    5. Connect a vinyl tube to the bleeder plug of the actuator.
    6.  
    7. Use the SST to boost pressure in the reservoir. Standard pressure is 50 to 80 kPa (0.5 to 0.8 kgf/cm2, 7.3 to 11.6 psi)
    8.  
    9. Drain approximately 100 cc of fluid.
    10.  
    11. Tighten the bleeder plug and boost the pressure in the reservoir again (50 to 80 kPa (0.5 to 0.8 kgf/ cm2)). Then, loosen the bleeder plug and bleed the brake actuator hose.
      NOTE
      Repeat this procedure at least 5 times.

    12.  
    13. When air is completely bled out from the hose between the reservoir and the actuator, tighten the bleeder plug to 74 inch lbs. (8.3 Nm).
    14.  

  6.  
  7. Bleed the master cylinder, as follows:
    NOTE
    If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

    1. Enter the following menus: DIAGNOSIS / OBD/MOBD / ABS/TRAC/VSC / AIR BLEEDING.
    2.  
    3. Select "USUAL" if the front/rear brakes are removed, installed or disassembled.
    4.  
    5. Select "ACTUATOR" if the actuator is removed, installed or replaced.
    6.  
    7. Select "MASTER CYLINDER" if the brake master cylinder or the brake stroke simulator is removed, installed or replaced.
    8.  
    9. Disconnect the brake lines from the master cylinder.
    10.  
    11. Slowly depress and hold the brake pedal (Procedure A).
    12.  
    13. Cover the outer holes with fingers, and release the brake pedal (Procedure B).
    14.  
    15. Repeat procedure A and B 3 or 4 times.
    16.  
    17. Connect the brake lines to the master cylinder and tighten to 11 ft. lbs. (15 Nm).
    18.  

  8.  
  9. Bleed the front brake system, as follows:
    NOTE
    Air can be easily bled from the front brake system if air has been bled from the master cylinder when replacing the brake master cylinder assembly.


    WARNING
    If brake fluid leaks onto any painted surface of the vehicle, wash or otherwise remove it completely.


    NOTE
    Bleed the air by following the steps displayed on the intelligent tester. (a) Depress the brake pedal several times and bleed the front brake system from the bleeder plugs on the front brake cylinder RH and LH.


    NOTE
    Repeat the procedure until air is completely bled from the front brake system.

  10.  
  11. Tighten the bleeder plugs to 74 inch lbs. (8.3 Nm) after bleeding.
  12.  
  13. Cancel brake control (ECB) disable
    1. Install the 2 motor relays (skid control relay No.2) if they have been removed.
    2.  
    3. Complete brake control prevention following the prompts on the tester screen. (If brake control has been prevented using the intelligent tester.)
    4.  

  14.  
  15. Clear the DTC(s).
  16.  
  17. Bleed the rear brake system, as follows:
    WARNING
    Never bleed air from the brake hydraulic system without using the intelligent tester. Failure to use the intelligent tester could cause serious injury or an accident.


    NOTE
    Bleed the air by following the steps displayed on the intelligent tester.

    1. Connect the intelligent tester to the DLC3 with the ignition switch off.
    2.  
    3. Check that the parking brake is applied and turn the ignition switch to the ON position.
    4.  
    5. Enter the following menus: DIAGNOSIS / OBD/ MOBD / ABS/TRAC/VSC / ECB UTILITY / ECB INVALID.
    6.  
    7. With the brake pedal depressed, bleed the rear brake system from the bleeder plug on the rear disc brake cylinder LH while the pump motor and solenoid are operating.
      WARNING
      Keep the fluid inside the reservoir above the LOW level by replenishing.


      NOTE
      Depress and hold the brake pedal. After the solenoid operates for approximately 30 seconds, release the brake pedal to stop the solenoid. Repeat the procedures until air is completely bled from the rear brake system. The ECB warning light comes on and the buzzer sounds while bleeding, but they do not indicate a malfunction.

    8.  
    9. Tighten the bleeder plug to 74 inch lbs. (8.3 Nm) after bleeding.
    10.  
    11. Enter the following menus: DIAGNOSIS / OBD/ MOBD / ABS/TRAC/VSC / ECB UTILITY / ECB INVALID.
    12.  
    13. With the brake pedal depressed, bleed the rear brake system from the bleeder plug on the rear disc brake cylinder RH while the pump motor and solenoid are operating.
      WARNING
      Keep the fluid inside the reservoir above the LOW level by replenishing.


      NOTE
      Depress and hold the brake pedal. After the solenoid operates for approximately 30 seconds, release the brake pedal to stop the solenoid. Repeat the procedures until air is completely bled from the rear brake system. The ECB warning light comes on and the buzzer sounds while bleeding, but they do not indicate a malfunction.

    14.  
    15. Tighten the bleeder plug to 74 inch lbs. (8.3 Nm) after bleeding.
    16.  

  18.  
  19. Perform the accumulator zero down:
    WARNING
    Never bleed air from the brake hydraulic system without using the intelligent tester. Failure to use the intelligent tester could cause serious injury or an accident. Be sure to perform this procedure before replacement, removal, or installation of the actuator.


    NOTE
    Perform accumulator zero down by following the steps displayed on the intelligent tester.

    1. Connect the intelligent tester to the DLC3 with the ignition switch OFF .
    2.  
    3. Depressurize the accumulator:

      Check that the parking brake is applied and turn the ignition switch to the ON position.
       
      Enter the following menus: DIAGNOSIS / OBD/ MOBD / ABS/TRAC/VSC / ECB UTILITY / ZERO DOWN.
       
      When the buzzer sounds, turn the ignition switch OFF .
       

    4.  
    5. Circulate the fluid in the accumulator.
    6.  
    7. Depressurize the accumulator 5 times.
      NOTE
      Accumulator pressure is released and accumulated repeatedly, which circulates the fluid inside the accumulator, when repeating accumulator zero down. The pump motor rotates and the accumulator is pressurized every time the ignition switch is turned from off to on.

    8.  

  20.  
  21. Check the brake fluid level:
    1. After performing accumulator zero down (accumulator depressurizing), return the fluid in the accumulator back to the reservoir and then adjust the fluid level in the master cylinder reservoir to the MAX level.
      NOTE
      After performing accumulator zero down (accumulator depressurizing), fluid is built up in the accumulator by turning the ignition switch to the ON position and the fluid level of the reservoir lowers. If the fluid level is adjusted without performing accumulator zero down (accumulator depressurizing), fluid is sent from the accumulator to the reservoir. The fluid level may exceed the MAX level, but it is normal.

    2.  

  22.  
  23. Clear the DTC(s).
  24.  
  25. When the brake actuator assembly is replaced, perform linear valve offset learning after bleeding is completed
  26.  

 
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