Doosan GV158TIC, Руководство по эксплуатации и техническому обслуживанию

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Disassembly and Reassembly of Major Components - 70 -
2) Piston inspection
●
With naked eyes, inspect the piston
for any wear, crack and scratch and
particularly inspect carefully at the ring
grooves for any wear.
●
With the outside micrometer, measure
the piston's out side diameter the
measuring position is 71.5 mm from
the piston lower end, and the direction
of measurement must be perpendicu-
lar to the piston pin direction.
●
By comparing the measured value of
the piston outside diameter with the
cylinder liner inside diameter, the big-
ger clearance is replaced.
3) Piston ring and ring groove
●
In case of piston ring's wear, damage
or engine overhaul, replace piston
rings.
●
Insert the piston ring at the cylinder
liner's upper part perpendicularly.
●
With a feeler gauge, measure the gap
clearance of piston ring.
●
If the measured value exceeds the
limit value, replace it.
<Piston ring gap>
71.5mm
Standard
ø127.739 - ø127.757 mm
Division Standard Limit
Top ring 0.30 ~ 0.45 mm 1.5 mm
2nd ring 0.40 ~ 0.60 mm 1.5 mm
Oil ring 0.4 ~ 0.7 mm 1.5 mm