It is not supposed to clear pistons an emery paper or a metal brush.

At visual survey will pay special attention on a surface of a shirt of the piston, проточки for rings, the piston bottom on presence of wear tracks and рисок. Pistons and piston fingers are pair details. The micrometer of the corresponding size is necessary for measurement of external diameter of the piston for you. Measurement of diameter make, turning a micrometer on 90 . The pistons having ovality above admissible values, it is necessary to replace.

Fig. 162. Measurement backlashes in a joint of a piston ring

Backlash in a joint of a piston ring measure by means of measuring щупа. For this purpose put separately piston ring on depth about 30 mm in the cylinder and measure a backlash with the help щупа (fig. 162).

Fig. 163. Measurement of a backlash of piston rings on height

The backlash on height on the established piston rings is measured щупом (fig. 163).