Steering Accumulator Charging Procedure - Komatsu 830E Shop Manual

10. Connect a hydraulic power supply to the oil port
on the accumulator. Be sure bleed plug (12,
Figure 5-5) is installed.
11. Pressurize accumulator with oil to 3,500 psi
(24132 kPa). This may take 6-8 gallons of oil.
12. No external oil leakage is permitted.
13. Slowly relieve oil pressure and remove hydraulic
power supply. Install plastic cover over hydrau-
lic port to prevent contamination.
14. If any gas or oil leakage was present, discharge
all nitrogen gas using the charging equipment
and repair as necessary. If there were no leaks
of any kind, then use the nitrogen charging
equipment and adjust nitrogen precharge pres-
sure to 100 - 120 psi (690 - 827 kPa).
Always store bladder accumulators with 100 -
120 psi (690 - 827 kPa) nitrogen precharge pres-
sure. Do not exceed 120 psi (827 kPa). Storing
accumulators with more than 120 psi (827 kPa)
pressure is not safe in case of leaks.
15. Verify all warning and caution labels are
attached and legible. Refer to parts book if
replacements are required.
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 to 1400 psi (9653
kPa) while installed on the truck. Never handle
accumulator with lifting equipment with a nitro-
gen precharge of 1400 psi (9653 kPa). Always set
precharge to 100 - 120 psi (690 - 827 kPa) before
handling (removing or installing) accumulators.
L5-6
NOTE: If one accumulator is low on nitrogen, it is
recommended that both accumulators be checked/
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. Remove charging valve cover. Be certain oil
pressure has been relieved, then remove bleed
plug (12, Figure 5-5).
NOTE: On the front accumulator, bleed plug (12)
must be removed during charging procedure to
insure there is no trapped oil or air inside
accumulator which will affect the nitrogen precharge
pressures. If only the rear most accumulator is being
charged, both brake accumulator bleed down valves
can be opened instead of removing bleed plug (12).
Nitrogen pressure is present in the accumulator.
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.
3. Remove charging valve cap (1, Figure 5-6). Turn
small swivel hex nut (4) three complete turns
counterclockwise.
4. If a loss in nitrogen pressure is the reason for
recharging, inspect the charging valve and
accumulator for damage. Replace or repair
items, as necessary, before charging proce-
dure.
5. Connect the nitrogen charging kit to the charg-
ing valves.
a. If the nitrogen precharge is to be bled off,
b. If the precharge is 0 psi, open the regulator
NOTE: The bladder could be permanently damaged
if it is charged too quickly before it is fully expanded.
c. If the precharge is already above 100 psi
Steering Component Repair
open the needle valve and slowly bleed off
the pressure.
and SLOWLY charge until the bladder is fully
expanded (approximately 100 psi, 690 kPa).
Once the bladder is fully expanded, the
charging rate can be increased.
(690 kPa), open the regulator and charge the
accumulator to 1400 psi (9653 kPa).
L05026