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Home >> Nissan-Datsun >> 2021 >> NV2500 HD S >> Repair and Diagnosis >> External Pages >> Different car >> Section 76 (Engine Mechanical) >> Removal And Installation >> Cylinder Head >> Inspection After Disassembly >> Valve Seat Replacement

Valve Seat Replacement

WARNING: This page is about a different car, the 2018 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
  1. Bore out old seat (A) until it collapses. Boring should not continue beyond the bottom face of the seat recess in cylinder head. Set the machine depth stop to ensure this.
    GNSAWBIA2409Z-409Courtesy of NISSAN NORTH AMERICA, INC.
  2. Ream cylinder head recess for service valve seat. Refer to Cylinder Head 

    Be sure to ream in circles concentric to the valve guide center. 

    This will enable valve seat to fit correctly. 

  3. Heat cylinder head to 110 - 130°C (230 - 266°F) by soaking in heated oil (A).
    WARNING: Cylinder head contains heat. when working, wear protective equipment to avoid getting burned.
    GNSAWBIA2407Z-407Courtesy of NISSAN NORTH AMERICA, INC.
  4. Press fit valve seat until it seats on the bottom.
  5. Cut or grind valve seat using suitable tool to the specified dimensions. Refer to Cylinder Head .
  6. After cutting, lap valve seat with abrasive compound.
  7. Check valve seating condition. Refer to Cylinder Head .
    G04159865Courtesy of NISSAN NORTH AMERICA, INC.
  8. Use a depth gauge to measure the distance between the mounting surface of the cylinder head spring seat and the valve stem end on the exhaust (A) and intake (B) sides. If the distance is shorter than specified, repeat step 5 to adjust it. If it is longer, replace the valve seat with a new one. Refer to Cylinder Head .
    GNSAWBIA2410Z-410Courtesy of NISSAN NORTH AMERICA, INC.
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