Control And Regulation Of The Pressures In The Hydraulic Circuits - Komatsu PC20R-8 Shop Manual

TESTING AND ADJUSTMENTS
CONTROL AND REGULATION OF THE PRESSURES IN THE
HYDRAULIC CIRCUITS
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
SCAMBIATORE COOLER
TANK
SERBATOIO
DIESEL
DIESEL
The control valve consists of the spools that command:
.
Command
Swing (R.H. - L.H.)
Travel motor L.H.
(Forwards - Backwards)
Travel motor R.H.
(Forwards - Backwards)
Boom swing (R.H. - L.H.)
Blade (Raise - Lower)
Arm (Close - Open)
Boom (Lower - Raise)
Bucket (Dump - Curl)
Hammer (Suction - Delivery)
PC20R-8 PC27R-8
CONTROL AND REGULATION OF THE PRESSURES
IN THE HYDRAULIC CIRCUITS
P1 P2
Ports
A1 - B1
A2 - B2
A3 - B3
A4 - B4
A5 - B5
A6 - B6
A7 - B7
A8 - B8
A9 - B9
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».
1 2
3
A
1 2 3
B
4
RKP06470
4 5 6 7 8 9
RKP06460
20-39