Komatsu 830E-AC Shop Manual page 569

9. Recheck pressures after cycling. If they have
changed, re-adjust pressures.
10. Shut down the test bench and relieve all
hydraulic pressure from the lines.
Avoid spillage and contamination! Avoid contact
with hot oil if the machine has been operating.
The oil will be at very high pressure.
Hydraulic fluid escaping under pressure can
have sufficient force to enter a person's body by
penetrating the skin and cause serious injury and
possibly death if proper medical treatment by a
physician familiar with this injury is not received
immediately.
11. Remove hoses from valve and remove valve
from test stand. Refer to instructions below for
pedal actuator installation prior to final test.
Final Test and Adjustment
The brake pedal actuator must be installed on the
brake valve body prior to final test and adjustment.
Refer to "Installation of Brake Pedal actuator to
Brake Valve"
NOTE: The "Final Test and Adjustment" procedure
can also be performed with the brake valve installed
in the truck. To perform final test with brake valve
mounted in the truck, install valve per instructions in
"Installation". Install 24 132 kPa (3,500 psi) gauges
at the BF and BR diagnostic test connectors in the
brake cabinet. Follow steps 18. - 29 below for final
test.
12. Reinstall brake valve (with actuator pedal
attached) on the test stand following steps 2
through 9 under "Test Setup Procedure".
J03034
13. With test stand pump adjusted for 22 064 kPa
(3,200 psi) or with engine running and brake
system supply pressure at or above 20 685 kPa
(3,000 psi), depress the pedal as quickly as
possible. The pressure on the output circuits
must reach the minimum pressure listed below
at port "B1" and port "B2" within 1.0 seconds.
Measurement of time begins the moment force
is applied to move the pedal.
14. With "B1" and "B2" plugged into a strip chart
recorder, (if available) check the modulation by
slowly applying pressure until the maximum
pressure is reached. Make sure the pressure
increase is smooth and no sticking of the spools
is observed. Fully depress the pedal. Pressures
must remain within specification at "B1" and
"B2" for 20 seconds.
15. Turn set screw (10, Figure 3-10) out (counter-
clockwise) so that set screw is not touching the
actuator cap. Apply Locktite® 242 to the adjust-
ment screw prior to setting the deadband.
16. Set the deadband by placing a 0.25 mm (0.010
in.) thick shim at location (11) between the
pedal structure and return stop boss on pivot
structure.
17. Turn the set screw (10) in (clock-wise) just until
the set screw is touching the cap.
18. Continue turning the set screw clock-wise until
pressure begins to rise on one of the brake
apply pressure gauges.
19. Back-off the set screw 1/8 turn (counter-clock-
wise).
20. Tighten the jam nut (9) and remove the shim
stock inserted in step 21.
Brake Circuit Component Service
Rear Brake - "B1" ("BR" on truck): 10 894 ±
517 kPa (1,580 ± 75 psi)
Front Brake - "B2" ("BF" on truck): 20 685 ±
1034 kPa (3,000 ± 150 psi)
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