Komatsu 830E, Shop Manual

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L05026 Steering Component Repair L5-23
Disassembly
When disassembling or assembling unit, choose
a work area where no traces of dust, sand or
other abrasive particles which could damage the
unit are in the air. Do not work near welding,
sand-blasting, grinding benches and the like.
Place all parts on a CLEAN surface. To clean
parts which have been disassembled, it is impor-
tant CLEAN solvents are used. All tools and
gauges should be clean prior to working with
these units and new, CLEAN and threadless rags
used to handle and dry parts.
1. Drain off excess hydraulic oil from pump inlet
and discharge ports. It may be necessary to
loosen the four valve plate capscrews (20, Fig-
ure 5-25) pull back on valve plate to allow fluid
to seep out of the case.
2. Thoroughly clean and dry the outside surface of
the pump housing.
NOTE: Depending upon what part or parts are to be
inspected, it may not be necessary to completely
take apart all assemblies.
Control Piston Group
3. Remove the two large plugs (23, Figure 5-23)
with O-rings (15) from both sides of pump.
4. Back out four capscrews (3, Figure 5-25), then
remove cap (24). Remove bias control spring
(1, Figure 5-24).
5. Control piston (11, Figure 5-24) must be in the
“neutral” position. Control link pin (16) should be
centered in the plug opening. If pin is not cen-
tered, pry control piston to position link pin for
access through hole.
6. Using appropriate snap ring pliers, remove
retaining rings (14, Figure 5-24) from both sides
of the pin and remove control link washers (15).
7. For handling purposes, insert a 1/4"-20UNC
capscrew into the threaded end of the control
link pin (16).
8. Using a brass rod and hammer, tap on end
opposite the capscrew to remove control link
pin (16).
Maximum volume stop gland (14, Figure 5-23)
MUST be removed BEFORE further disassembly
of control piston.
9. Without disturbing jam nut (16, Figure 5-23),
unscrew gland (14) and remove stroke adjuster
as a complete assembly.
Valve Plate Group
NOTE: Valve plate (17, Figure 5-25) is a slight press
fit in the pump housing (20, Figure 5-23).
10. Support valve plate (17, Figure 5-25) from an
overhead crane (lifting lug holes are provided)
and remove four capscrews (20) from valve
plate.
11. Remove valve plate (17) from pump housing (20,
Figure 5-23) by tapping away from the housing
with a mallet until valve plate pilot diameter dis-
engages from the case 0.25 in (6.35 mm).
12. With the weight of the valve plate still suspended
from the overhead crane, slide valve plate back
until it disengages from driveshaft and set valve
plate aside. Care must be taken not to damage
the wear face of valve plate (17).
13. To further disassemble control piston assembly,
move control piston (11, Figure 5-24) into
sleeve (4) until control piston maximum stop pin
(8) contacts the sleeve. Use a large mallet to
drive piston and sleeve assembly outward from
the valve plate.
14. When all sleeve seals (5, 6, & 7) are clear of the
valve plate, re-extend control piston (11). While
tipping the assembly enough to clear the hole,
pull the assembly from the valve plate.
15. Remove pin (18) from control piston by pressing
or tapping it out through the hole on opposite
side. Control stop pin (8) can be removed and
control piston (11) slipped out of sleeve (4).
16. Remove capscrews (9, Figure 5-25) and remove
compensator block (13).
17. Remove capscrews (21) and cover plate (19).