Komatsu 830E-AC Shop Manual page 693

STEERING ACCUMULATOR CHARGING
PROCEDURE
Do not loosen or disconnect any hydraulic line or
component until engine is stopped and key
switch has been OFF for at least 90 seconds.
Pure dry nitrogen is the only gas approved for
use in the steering accumulator. The accidental
charging of oxygen or any other gas in this com-
partment may cause an explosion. Be sure pure
dry nitrogen gas is being used to charge the
accumulator.
When charging or discharging nitrogen gas in
the accumulator, be sure the warning labels are
observed and the instructions regarding the
charging valve are carefully read and under-
stood.
Only precharge accumulators while installed on
the truck. Never handle accumulator with lifting
equipment with a nitrogen precharge more than
827 kPa (120 psi). Always set precharge to 690 -
827 kPa (100 - 120 psi) for storage or before
removing or installing accumulators.
NOTE: If one accumulator is low on nitrogen, it is
recommended that both accumulators be checked
and or charged at the same time.
1. With engine shut down and key switch in the
OFF position, allow at least 90 seconds for the
accumulator to bleed down. Turn the steering
wheel to be certain no oil remains in accumula-
tor under pressure.
2. Be certain oil pressure has been relieved, then
remove bleed plug (12, Figure 5-5) from each
accumulator being charged.
NOTE: If a new or rebuilt accumulator (or any
bladder accumulator with all nitrogen discharged) is
being precharged while installed on the truck and
connected to the hydraulic system, the oil side of the
accumulator must be vented to allow proper bladder
expansion. This is done by removing the bleeder
plugs described above. Trapped air or oil on the
hydraulic side of the bladder will prevent the proper
precharge pressure from being obtained for safe
operation.
L05035
3. Remove charging valve cover (5, Figure 5-3).
4. Close all valves (1, 2 & 8, Figure 5-7).
5. Install charging manifold assembly to the nitro-
gen gas supply tank. Open valve on nitrogen
supply tank.
.
Nitrogen pressure may be present in the accumu-
lator. Make certain only the small swivel hex nut
is turned during the next step. Turning the com-
plete valve assembly may result in the valve
assembly being forced out of the accumulator by
the nitrogen pressure inside.
6. Hold gas valve stationary at valve body (6, Fig-
ure 5-6) with one wrench and loosen swivel nut
(4) at top with a second wrench. This will open
the poppet inside the gas valve.
NOTE: Three turns will fully open the valve.
FIGURE 5-6. CHARGING VALVE
1. Valve Cap
2. Seal
3. Valve Core
4. Swivel Nut
(Small Hex Nut)
5. Rubber Washer
Steering Component Repair
6. Valve Body
(Large Hex Nut)
7. O-Ring
8. Valve Stem
9. O-Ring
L5-9