Komatsu 830E-AC Shop Manual page 777

ACCUMULATOR BLEED DOWN
PROCEDURE
To safely relieve hydraulic pressure in the accumula-
tors while performing leakage tests, follow these
steps.
Parts required:
a. Hose - 1/4" SAE 100R2 rated at 34474 kPa
(5,000 psi)
or - 3/8" SAE100R2 rated at 27579 kPa
(4,000 psi)
b. Two needle valves rated at 27579 kPa
(4,000 psi)
c. One Tee connector
d. One fitting to connect hose to hydraulic tank
filler tube.
1. Before performing any tests, with engine OFF
and accumulators bled down, attach a hose and
needle valve assembly to each accumulator
bleed port.
2. Connect the two hoses (one from each needle
valve) together using a tee connector, then con-
nect the remaining hose end to a fitting that
screws into the hydraulic tank filler tube (in
place of the filler cap).
3. By opening the needle valves, both accumula-
tors can be bled down and the oil discharged
back into the hydraulic tank.
L10028
LOW STEERING PRESSURE SWITCH
1. Shut down engine and turn key switch OFF.
Wait 90 seconds for steering accumulator to
bleed down. Turn steering wheel to be sure no
pressure remains.
2. Connect a calibrated 35,000 kPa (5000 psi)
pressure gauge to the rear accumulator.
3. Start truck and observe at least 21 718 kPa
(3150 psi) on gauge. Shut engine down using
kill switch on center console (not key switch).
4. Slowly bleed off accumulator pressure by open-
ing needle valves in brake cabinet. Observe the
pressure value when the Low Steering Pressure
warning light and buzzer are activated. Activa-
tion range must be within 15 858 ± 317 kPa
(2300 ± 46 psi) falling. If outside this range,
replace pressure switch.
Hydraulic Check-out Procedure L10-9