Komatsu F30791, Shop Manual

Page: 166 / 298

CONTROL AND REGULATION OF THE SERVO-CONTROL
POWER SUPPLY
20-50
TESTING AND ADJUSTMENTS
CONTROL AND REGULATION OF THE
SERVO-CONTROL POWER SUPPLY
H Test conditions:
.
Engine: at working temperature.
. Hydraulic oil temperature: 45 ± 55 ëC.
Before removing the cap to measure the pressure,
release the residual pressures from the circuits
(See «ELIMINATION OF RESIDUAL PRESSURES
OF THE CIRCUIT AND THE TANK») and put the
safety device engagement levers into their locked
position.
After connecting the pressure gauge, pressurise the
tank. For details see «PRESSURISATION OF THE
TANK».
1. Checking the pressure of the servo-controls
1 - Remove the R.H. hood (1).
2 - Remove the cap (2) of pump P2 and a pressure
adapter.
3 - Connect the pressure gauge E1 (60 bar).
4 - Start the engine and bring it up to high idling with
all leers in neutral position.
5 - Check the pressure.
H Normal pressure: 29
5
bar (30
5
kg/cm
2
)
2. Regulating the servo-control valve
If the pressure value does not fall within the toler-
ances, regulate the valve (3) as follows:
1 - Loosen the lock nut (4) and turn the adjusting
screw (5).
. To INCREASE pressure, rotate in a CLOCK-
WISE direction.
.
To DECREASE pressure, rotate in a COUN-
TER-CLOCKWISE direction.
H Each turn of the screw (5) varies the pressure
by 56 kg/cm
2
(55 bar).
2 - Lock the nut (4).
Nut: 22 w 2.5 Nm
PC20R-8 PC27R-8
RKPA2420
1
RKPA2430
E
1
3
2
RKP06420
4
5