Komatsu PC500LC-10R, Shop Manual, Page: 200 / 758

FUNCTION OF HYDRAULIC TANK OIL FILLER CAP
Prevention of pressure rise in hydraulic tank
While the hydraulic circuit is in operation, the pressure in the hydraulic tank increases as the oil level and the
temperature in the hydraulic tank rise corresponding to the operation of the hydraulic cylinders. When the pres-
sure in the tank exceeds the set pressure, bottom plate (1) is pushed up to release the pressure in the tank and
prevent pressure rise.
(Set pressure of exhaust valve: 16.7 ± 6.86 kPa {0.17 ± 0.07 kg/cm
2
} )
HYDRAULIC TANK BREATHER
STRUCTURE OF HYDRAULIC TANK BREATHER
Sectional view
1: Nut
2: Cover
3: Filter element
4: Case
5: Valve assembly
6: Body
FUNCTION OF HYDRAULIC TANK BREATHER
Prevention of negative pressure in hydraulic tank
Since the hydraulic tank is pressurized and sealed, if the oil level in it decreases, negative pressure is generated
in it. At this time, valve assembly (5) is opened by the differential pressure from the ambient pressure, and ambi-
ent pressure is transmitted into the tank to prevent generation of negative pressure in the tank
(Set pressure of intake valve: 2 ± 0.3 kPa {0.02 ± 0.003 kg/cm
2
} )
BYPASS VALVE STROKE SENSOR OF HYDRAULIC TANK
STRUCTURE OF BYPASS VALVE STROKE SENSOR OF HYDRAULIC TANK
General view
COMPONENT PARTS OF HYDRAULIC SYSTEM 10 STRUCTURE AND FUNCTION
10-106 PC500LC-10R