Komatsu F30791, Shop Manual

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CONTROL AND REGULATION OF THE PRESSURES IN THE
HYDRAULIC CIRCUITS
20-39
TESTING AND ADJUSTMENTS
CONTROL AND REGULATION OF THE PRESSURES
IN THE HYDRAULIC CIRCUITS
. The control valve consists of the spools that command:
Command Ports
Swing (R.H. - L.H.) A1 - B1
Travel motor L.H.
(Forwards - Backwards)
A2 - B2
Travel motor R.H.
(Forwards - Backwards)
A3 - B3
Boom swing (R.H. - L.H.) A4 - B4
Blade (Raise - Lower) A5 - B5
Arm (Close - Open) A6 - B6
Boom (Lower - Raise) A7 - B7
Bucket (Dump - Curl) A8 - B8
Hammer (Suction - Delivery) A9 - B9
PC20R-8 PC27R-8
RKP06460
1 2 3 4 5 6 7 8 9
A
B
H Test conditions:
.
Engine: at working temperature.
. MIN and MAX. engine speeds: within permissi-
ble limits.
. Hydraulic oil: 45 ± 55 ëC.
Before removing the plugs in order to measure the
pressures, release the residual pressures in the
circuits (see «ELIMINATION OF THE RESIDUAL
PRESSURES IN THE CIRCUITS AND IN THE
TANK») and place the safety engagement levers
into their locked positions.
After having connected the pressure gauges, pres-
surise the tank. For details, see «PRESSURISA-
TION OF THE TANK».
RKP06470
2 1
3
DIESEL
P1 P2
SERBATOIO
SCAMBIATORE
4
COOLER
TANK
DIESEL