ENGINE UNIT (for DPF) REPAIR


  1. BORE CYLINDER

    Tech Tips


    • Bore all 4 cylinders for the O/S piston outside diameter.

    • Replace all the piston rings with ones to match the O/S pistons.


    1. Prepare 4 new O/S pistons.

      Standard piston diameter
      92.42 to 92.45 mm (3.6386 to 3.6398 in.)
    2. A01DWF0E01
      Text in Illustration
      *1 Size Mark
      *2 Piston Pin Hole Inside Diameter Mark
      *3 Front Mark (Arrow)
      *4 Distance

      Using a micrometer, measure the piston diameter according to the following conditions: 1) measure at a right angle to the piston center line, and 2) measure at the indicated distance from the piston head.

      Distance
      63.5 mm (2.50 in.)

    3. Calculate how much each cylinder needs to be rebored:

      Size to be rebored
      Size to be rebored = P + C - H
      P = Piston diameter
      C = Piston clearance: 0.07 to 0.09 mm (0.0028 to 0.0035 in.)
      H = Allowance for honing: 0.02 mm (0.0008 in.) or less

    4. Bore and hone the cylinders to the calculated dimensions.

      Maximum honing
      0.02 mm (0.0008 in.)

      Note

      Excess honing will destroy the finished roundness.