2.9.15.3. Survey and restoration of pistons and piston rings

 PERFORMANCE ORDER

  1. If pistons are installed back on the engine, carefully remove piston rings, having moved apart each of them exactly so to remove through a crossing point between flutes on a piston body.
  2. To prevent falling of rings it is recommended to insert two or three narrow strips of a tin (old plates of the probe) under a ring into the flute located above as equals distances from each other, and then to twist a ring from the piston.
  3. Clear flutes and rings of a deposit so that not to scratch the aluminum surfaces of the piston.
  4. If new rings are established, the top compression ring has to have the step form to avoid its blows about "a wear ring" which was formed in the top part of an opening of the cylinder.
  5. Before final installation of rings on pistons measure gaps in locks of rings. These gaps have to conform to technical requirements.
  6. Execute check by the probe of a side gap of rings on compliance technical requirements. If the gap is too big, replace the piston since its flute is worn-out on height.
  7. Establish rings and deploy their locks evenly on a piston circle (on 120 °).