Seizure due to insufficient clearance at the bottom skirt end

• Seizure due to insufficient clearance at the bottom skirt ends, with wear marks and counter-wear marks.
• The marks change from bright wear marks to smooth, darkly discoloured areas of wear caused by rubbing (Fig. 1).
• There is nothing unusual about any of the remaining parts of the piston.
• Seizure marks in the cylinder liner in the area around the lower O-rings (Fig. 2).

The piston seizure at the bottom edge of the piston skirt was caused by distortion/restricted clearances in the lower area of the cylinder liner.

• Incorrect sealing rings: excessively thick sealing rings can distort a cylinder liner and reduce the piston running clearance.
• Additional use of liquid sealants in the sealing ring groove. In order to seal the surfaces, the sealing rings must be able to deform elastically. The free space required for this in the groove must not be filled with additional sealant.
• Any sealing ring residue or dirt in the sealing ring grooves was not removed prior to installation.
• If the sealing rings twist when the cylinder liner is being inserted or slip out of the sealing ring groove, the cylinder liner will become constricted in this area. To prevent this, lubricant must always be used when installing the cylinder liner.