LOAD SENSING PROPORTIONING VALVE(w/o ABS) ON-VEHICLE INSPECTION

PROCEDURE


  1. CHECK LOAD SENSING PROPORTIONING VALVE ASSEMBLY

    A01LEFSC03
    *a Weight

    1. Set the vehicle to its curb weight.

    2. Place weights (as necessary) on the rear deck until the rear axle load is as shown below.

      Standard Rear Axle Load
      Vehicle Type Specified Condition
      for Single Cab 7354 N (750 kgf, 1651 lbf)
      for Double Cab 8336 N (850 kgf, 1874 lbf)

      Note


      • Be sure that the vehicle is on a level surface before starting the procedure.

      • When placing the weights on the vehicle, first place the weights so that the total is approximately 60 kg (132 lb) more than the specification. Then remove weights as necessary to adjust the load.

    3. A01LFJ0N01

      Install SST and bleed air from the brake system.

      SST
      09709-29018
    4. A01LDTSN01

      Raise the front brake fluid pressure to 10000 kPa (107.6 kgf/cm2, 1450 psi) by depressing the brake pedal, and measure the rear brake fluid pressure.

      Standard rear brake fluid pressure
      5260 +/-490 kPa (53.6 +/-5.0 kgf/cm2, 763 +/-71 psi)

      Tech Tips


      • The pedal should not be depressed twice or released while raising the front brake fluid pressure.

      • Read the value of the rear brake fluid pressure after raising and holding the front fluid pressure for 2 seconds.

      If necessary, adjust the load sensing proportioning valve.

  2. ADJUST LOAD SENSING PROPORTIONING VALVE ASSEMBLY


    1. A01LCCEN01

      Adjust the length of the No. 2 load sensing spring shackle.

      When the rear brake fluid pressure is below the standard pressure, lengthen length A.

      When the rear brake fluid pressure is higher than the standard pressure, shorten length A.

      Standard initial length (A)
      120 mm (4.72 in.)
      Standard length after Adjustment (A)
      103 to 127 mm (4.06 to 5.00 in.)

      Tech Tips

      The rear brake fluid pressure changes as shown below by adjusting length A.

      Standard pressure change
      Changes by 140 kPa (1.4 kgf/cm2, 20.3 psi) for every 1 mm (0.0394 in.) change in length A
    2. A01LAHF

      If the pressure cannot be adjusted by the No. 2 load sensing spring shackle, loosen the nuts and raise or lower the valve body.

      When the pressure is below the standard pressure, lower the load sensing valve assembly.

      When the pressure is higher than the standard pressure, raise the load sensing valve assembly.

    3. Tighten the nuts.

      Torque:
      12.5 N*m  { 127 kgf*cm, 9 ft.*lbf }

    4. Adjust the length of the No. 2 load sensing spring shackle again.

      Tech Tips

      If the length cannot be adjusted, check the load sensing valve assembly.

  3. CHECK VALVE BODY


    1. Check that the master cylinder rear brake fluid pressure changes according to the rear wheel cylinder pressure.

      Standard Pressure
      Master Cylinder Pressure Wheel Cylinder Pressure

      2450 kPa (25 kgf/cm2, 355 psi)

      1350 +/-200 kPa (13.8 +/-2 kgf/cm2, 196 +/-29 psi)

      5880 kPa (60 kgf/cm2, 853 psi)

      2210 +/-340 kPa (22.5 +/-3 kgf/cm2, 321 +/-49 psi)

      If the result is not as specified, replace the load sensing valve assembly.