Disassembly - Komatsu 830E Shop Manual

6. Start the engine and bleed air from brake lines and
brakes. Actuate the brake lock switch and open
the uppermost bleeder screw on all rear brake
assemblies until a steady stream of oil appears.
Close bleeder screw.
7. Release the brake lock switch and bleed the
remaining front brakes in the same manner by
depressing the brake pedal. Check for fluid leaks
at the brake valve.

Disassembly

NOTE: If equipped with, and not already removed,
remove electronic retard pedal (16, Figure 3-3) from
brake pedal by removing pivot shaft (8). The rebuild
and adjustment procedures for the brake valve (1) are
the same, whether or not the brake pedal has the
retard pedal assembly attached to it.
NOTE: During disassembly, precision machined parts
should be ink marked or tagged to ensure proper
reassembly and minimize adjustment time. All items
must be placed back into the bores from which they
were removed.
1. Match mark each section of the brake valve prior
to disassembly.
FIGURE 3-4. ACTUATOR CAP & BOOT
1. Actuator Cap
2. Boot
3. Capscrew
4. Retainer Plate
J3-4
5. Capscrew
6. Actuator Base
7. Threaded Insert
Brake Circuit Component Service
2. Drain all oil from all ports of the valve by rotating
the valve over a suitable container.
3. Secure brake valve in an upright position in a vice.
4. Remove the brake pedal actuator (7, Figure 3-2)
by removing the retaining clips (2), then remove
the pivot shaft (3) with a punch and hammer.
5. Remove the four button head allen screws (3,
Figure 3-4) securing the boot retainer plate (4).
6. Remove the boot retainer plate (4), boot (2), and
actuator cap (1) as an assembly by grasping the
boot and gently lifting from the valve body.
7. Remove capscrews (36, Figure 3-5) and the dif-
ferential pressure switch (35).
8. Remove and discard the O-ring (27) and face seal
(28).
9. Loosen the plunger locknuts (2). Loosen the
socket head capscrew from the adjustment col-
lars (1).
10. Unscrew and remove the adjustment collars.
11. Remove the two socket head capscrews (5, Figure
3-4) that retain the actuator base (6) to the valve
body.
12. Remove the actuator base from the valve body.
13. Remove controller from vice.
14. Remove the four capscrews (34, Figure 3-5) and
washers (33) from the base of the valve.
15. Remove the base plate (32).
16. With the valve upright, the retaining plug (31)
should fall out. If the plug does not fall out, lightly
tap to dislodge the plug.
NOTE: The spools (12), reaction plungers (21, 22) and
spool return springs (20) may fall out at this time. Keep
parts separate so they may be installed in the same
bores from which they were removed.
The "B1" reaction plunger (21) is larger than the "B2"
reaction plunger (22).
17. Remove and discard the O-ring (30) from the
counterbore in the base of the valve body.
18. With the controller upright on the work bench, hold
the valve with one hand and push the "B1" actua-
tor plunger (3) down with the other hand until the
regulator sleeve (19) pops loose.
19. Repeat the above procedure to loosen the "B2"
regulator sleeve.
20. Turn the valve on its side on the work bench and
remove the regulator sleeves (19) from the valve
body.
J03022 1/99