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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Suspension >> Suspension Control Systems >> HBMC >> Basic Inspection >> Air Bleeding Method >> Work Procedure
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Work Procedure

WARNING:
  • Always check the piping for loose connections, damage, or twists before starting operation, since pressure in hydraulic circuit becomes high during operation.
  • When repairing or replacing a malfunctioning part, always release pressure from hydraulic circuit, since dangerous conditions may be created when oil leakage occurs during air bleeding operation.
CAUTION:
  • Clean surrounding areas of oil injection jack and air bleeder using steam before starting operation, since there may be mud on it.
  • Clean suspension oil pump (special service tool: KV40107700) jack with steam before use.
  • Check system pressure again 1 day or more after bleeding operation is complete, since system pressure may decrease when air bleeding is insufficient.
  1. Lift up the vehicle.
  2. Remove protector of PPMU.
  3. Remove cap of oil injection jack.
  4. Install hose (A) of a suspension oil pump (SST: KV40107700) to oil injection jack.
    CAUTION: Jack must be securely inserted until a click sound can be heard.
    Fig 1: Identifying Hose Of Suspension Oil Pump
    G07045675Courtesy of NISSAN MOTOR CO., U.S.A.
  5. Loosen pressure reducing valve (A) of hose portion of suspension oil pump.
    Fig 2: Identifying Pressure Reducing Valve Of Hose Portion Of Suspension Oil Pump
    G07045676Courtesy of NISSAN MOTOR CO., U.S.A.
  6. Set knob (A) of suspension oil pump to the direction as shown in the figure.
  7. Close pressure reducing valve of hose portion of suspension oil pump while sending oil by applying pressure using suspension oil pump. (Air bleeding in hose is complete.)
    Fig 3: Identifying Knob Of Suspension Oil Pump
    G07045677Courtesy of NISSAN MOTOR CO., U.S.A.
  8. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
    CAUTION: Never loosen the needle valve more than required.
  9. Install bleeder tube and drain tank to bleeder valve in upper side of rear shock absorber RH.
  10. Loosen bleeder valve and bleed air while sending oil by applying pressure using suspension oil pump, and then quickly tighten air bleeder.
    CAUTION: Be careful that oil in suspension oil pump is not at half or less.
    Fig 4: Identifying Needle Valves Of PPMU
    G07045669Courtesy of NISSAN MOTOR CO., U.S.A.
  11. Repeat step  10 until no air appears in bleeder tube.
  12. Tighten bleeder valve to the specified torque. Refer to "FRONT TUBE ASSEMBLY : EXPLODED VIEW " (front shock absorber), "PPMU, MIDDLE TUBE ASSEMBLY, PPMU PIPE : EXPLODED VIEW " (upper side of rear shock absorber).

    Lower side of rear shock absorber 

    Tightening torque : 8.3 N.m (0.85 kg-m, 73 in-lb) 

  13. Perform operation according to steps 9 to 12 in the order of rear shock absorber RH (lower side) → front shock absorber RH (upper side and lower side) → rear shock absorber LH (upper side and lower side) → front shock absorber LH (upper side and lower side).
  14. Repeat steps  9 to  13 (2nd turn).
  15. Refer to the figure and send oil by applying pressure.
    Fig 5: Pressure Versus Ambient Temperature Graph
    G07045679Courtesy of NISSAN MOTOR CO., U.S.A.
  16. Tighten needle valves A, C, and E of PPMU to the specified torque.

    Tightening torque : 8.3 N.m (0.85 kg-m, 73 in-lb) 

  17. Set knob (A) of suspension oil pump to the direction as shown in the figure and check that reading of pressure gauge is 0 MPa.
  18. Remove hose of suspension oil pump.
  19. Install cap of oil injection jack.
  20. Install protector of PPMU. Refer to "PPMU, MIDDLE TUBE ASSEMBLY, PPMU PIPE : EXPLODED VIEW ".
Fig 6: Identifying Knob Of Suspension Oil Pump
G07045680Courtesy of NISSAN MOTOR CO., U.S.A.
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