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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Suspension >> Suspension Control Systems >> HBMC >> Basic Inspection >> Check Orifice For Clogging >> Work Procedure
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Work Procedure

CAUTION:
  • Clean surrounding areas of oil injection jack using steam before starting operation, since there may be mud on it.
  • Clean oil pressure gauge (special service tool: KV40108000) jack with steam before use.
  1. Remove protector of PPMU.
  2. Remove cap of oil injection jack.
  3. Install an oil pressure gauge (SST: KV40108000) (A) to oil injection jack.
    CAUTION:
    • Jack must be securely inserted until a click sound can be heard.
    • Pressure reducing valve (B) of the oil pressure gauge must be closed.
    Fig 1: Identifying Suspension Oil Pump Hose And Pressure Reducing Valve
    G07045668Courtesy of NISSAN MOTOR CO., U.S.A.
  4. Loosen needle valves A, C, and E of PPMU by approximately 2 rotations.
    CAUTION: Never loosen the needle valve more than required.
  5. Lift up the vehicle.
    CAUTION: Check that tires never contact the ground.
  6. Tighten needle valves A, C, and E of PPMU.
  7. Lift down the vehicle.
    CAUTION: Check that the lift is fully lowered.
    Fig 2: Identifying Needle Valves Of PPMU
    G07045669Courtesy of NISSAN MOTOR CO., U.S.A.
  8. Loosen pressure reducing valve (A) of oil pressure gauge and then lower pressure.
    CAUTION: Be careful since oil drains swiftly from oil drain hole (B).
  9. Check that reading of oil pressure gauge is 0 MPa. Close pressure reducing valve.
  10. Loosen needle valve E of PPMU by approximately 2 rotations.
    CAUTION: Never loosen the needle valve more than required.
  11. Write down a value of the oil pressure gauge.
  12. Tighten needle valve E of PPMU.
    Fig 3: Checking Reading Of Oil Pressure Gauge
    G07045671Courtesy of NISSAN MOTOR CO., U.S.A.
  13. Loosen pressure reducing valve of oil pressure gauge and then lower pressure.
    CAUTION: Be careful since oil drains swiftly from oil drain hole.
  14. Check that reading of oil pressure gauge is 0 MPa. Close pressure reducing valve.
  15. Loosen needle valve A of PPMU by approximately 2 rotations.
    CAUTION: Never loosen the needle valve more than required.
  16. Read a value of the oil pressure gauge after 5 minutes.
  17. Compare difference of reading with pressure reading in step 11.

    Pressure difference 

    0.2 MPa or more : Replace the PPMU. Refer to  "PPMU, MIDDLE TUBE ASSEMBLY, PPMU PIPE : REMOVAL AND INSTALLATION ".

    0.2 MPa or less : Normal 

  18. Tighten needle valve A of PPMU.
  19. Loosen pressure reducing valve of oil pressure gauge and then lower pressure.
    CAUTION: Be careful since oil drains swiftly from oil drain hole.
  20. Check that reading of oil pressure gauge is 0 MPa. Close pressure reducing valve.
  21. Loosen needle valve C of PPMU by approximately 2 rotations.
    CAUTION: Never loosen the needle valve more than required.
  22. Read a value of the oil pressure gauge after 5 minutes.
  23. Compare difference of reading with pressure reading in step 11.

    Pressure difference 

    0.2 MPa or more : Replace the PPMU. Refer to  "PPMU, MIDDLE TUBE ASSEMBLY, PPMU PIPE : REMOVAL AND INSTALLATION ".

    0.2 MPa or less : Normal 

  24. Tighten needle valve C of PPMU.
  25. Loosen pressure reducing valve of oil pressure gauge and then lower pressure.
    CAUTION: Be careful since oil drains swiftly from oil drain hole.
  26. Check that reading of oil pressure gauge is 0 MPa.
  27. Remove oil pressure gauge.
  28. Tighten needle valves A, C, and E of PPMU to the specified torque.

    : 8.3 N.m (0.85 kg-m, 73 in-lb) 

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