Komatsu 830E-AC Shop Manual page 563

NOTE: Throughout the following steps, it is important
to keep the circuits and circuit components identified
as to which side of the unit they came from. For a
given circuit, all the components have a tolerance
stack which could vary. Keep the "B1" and "B2" parts
separate. Springs (5 & 6) are also different in "B1"
and "B2" bores.
21. Remove the regulator spools (8), reaction
plungers (16, 17) and spool return springs (15)
from the regulator sleeves (14).
22. Remove the plunger return springs (4), regula-
tor springs (5 & 6), and spring seats (7) from the
valve body.
23. Remove the actuator plungers (2) by pushing
down (toward the bottom of the valve) on the
actuator plunger with your hand until the actua-
tor plunger slides out.
24. Remove the glyde ring assembly (3) from the
actuator plunger.
25. Remove the O-rings (10, 12 & 13) and teflon
back-up rings (9 & 11) from the regulator
sleeves and discard.
26. Remove the wiper seals (18), poly-pak seals
(20), and the orange back-up rings (19) from
the actuator section of the valve and discard.
Cleaning and Inspection
1. Clean all metal parts with solvent and air dry.
2. Inspect the plunger (2, Figure 3-5) for wear on
the sides where it moves through the seals. If
axial grooves are seen or if any wear is appar-
ent, replace the plunger. Plungers with diameter
worn below 18.974 mm (0.747 in.) must be
replaced.
3. Place the regulating spool (8) into its sleeve
(14). Push the spool lightly through the sleeve.
The spool must be able to move freely and
smoothly the entire length of the sleeve. If it
cannot, it must be replaced. Never replace just
the spool or sleeve. They must be replaced as a
matched set.
J03034
4. Inspect each spring carefully for cracks or
breaks. Any spring with a crack or break must
be replaced. Also, if the valve was not reaching
proper regulated pressure, replace all regulator
springs.
5. Inspect the threaded inserts (7, Figure 3-4) in
the actuator base. If any of the threads are
damaged, the inserts must be replaced.
6. Lubricate all parts with a thin coat of clean type
C-4 hydraulic oil. Take care to keep compo-
nents protected from contamination.
ASSEMBLY
Actuator Base Threaded Inserts
1. If any inserts (7, Figure 3-4) were removed from
the actuator base (6), position the actuator base
upside down on the work bench and support
directly under each of the four floor mounting
holes.
2. Install the threaded inserts into the actuator
base by tapping lightly with a small hammer
until the insert flanges become flush with the
actuator base. Be sure the base is supported to
avoid breaking the base.
3. Thoroughly clean the actuator base and set
aside.
Boot and Cap
1. Examine the boot (2, Figure 3-4) for any cracks,
tears, or other damage. If damage is evident,
the boot must be replaced To replace the boot,
follow the procedure below.
2. Remove the boot from the actuator cap (1) and
discard the old boot. Thoroughly clean the sides
of the cap by scraping the lip where the cap
contacts the boot. Use a knife or suitable
scraper. Clean thoroughly to remove all residual
adhesive or particles of the old boot.
3. Apply a thin bead of Loctite Prism 410 onto the
upper sides of the cap. Apply the bead to the
two long sides only. Do not apply it to the
rounded ends, these must not be sealed to
allow the boot to breathe.
4. Carefully position the cap into the new boot
groove wiping off the excess glue.
5. Position the boot such that it conforms to the
contour of the cap, then set aside. Adhesive
requires about 30 minutes to cure.
Brake Circuit Component Service J3-9