2.5. The block of cylinders

At full dismantling carefully to clear the block of cylinders and to remove from cavities and lubricant channels all adjournment. The special attention is necessary for turning on full removal of the washing liquids used for clearing. If it is possible, to use for drying the compressed air.

For measurement of a working backlash of pistons to measure diameters of pistons (fig. 67 see) and to fix the received values.

Fig. 67. Measurement of diameter of the piston (on distance of 10 mm from the bottom edge of a skirt of the piston)

For definition of a working backlash it is necessary to measure internal diameter of the cylinder as follows:

- Using display нутромер, to measure diameter on distance of 10 mm from the top edge and then on the same distance from the bottom edge of the cylinder;

- To execute in addition one measurement in the middle;

- The specified measurements to spend in a longitudinal direction, and then once again at the same values of depth in a cross-section direction of the block. To write down results of all six measurements. We recommend to make the drawing, similar fig. 74, and in it to specify results of gauging. The difference between values of the top and bottom gaugings defines конусность, the difference between values of gauging in longitudinal and cross-section directions gives ovality. In one place diameter should not deviate from the nominal size more than on 0,04 mm. On fig. 74 values of deterioration (on the right) are resulted at normal operation () and at insufficient greasing (b).

Fig. 74. Measurement of internal diameters of cylinders

Pistons let out three repair sizes, if necessary the block should be chiseled in addition and хонинговать till next size.

The surface of the block of cylinders is checked on deformation the same as also a head of the block of cylinders. To measure the block by a metalwork ruler and щупом in longitudinal, cross-section directions and on a diagonal. Щуп in the thickness more than 0,10 mm should not enter into backlashes.