Komatsu 830E Shop Manual page 474

Control Piston Group
25. Install piston rings (2 & 3, Figure 5-24) into their
respective grooves on control piston (11) using
care to assure they are in proper location.
26. Insert control piston assembly into sleeve (4).
27. While supporting the control piston, press or slip
in pin (8) and secure with cotter or roll pin (18).
28. Order of piston sleeve seal installation starts at
widest end of sleeve.
29. Install backup ring (1, Figure 5-27) and O-ring
(2) and backup ring (3) in rear most groove on
piston sleeve. Install O-ring (4) and backup ring
(5) in remaining groove.
FIGURE 5-26. O-RING LOCATION ON PISTON
SLEEVE
1. Backup Ring
2. O-Ring
3. Backup Ring
30. Insert piston and sleeve assembly (4, Figure 5-
24) into valve plate (17, Figure 5-25).
31. Install O-ring (18) in rear of valve plate. Use four
capscrews (21) to fasten cover plate (19) over
opening in valve plate (17).
32. Pull free end of control link (17, Figure 5-24)
toward back of pump housing until the open
hole in the link lines up with open ports on sides
of pump case.
33. Install maximum volume stop gland (14, Figure
5-24) and adjusting screw (12) to hold swash-
block in place.
L5-30
4. O-Ring
5. Backup Ring
Steering Component Repair
Valve Plate Group
34. Be sure driveshaft bearing (15, Figure 5-25) is in
place. Using assembly grease (to hold desired
position), place valve plate gasket (16) in posi-
tion on valve plate (17).
35. Support valve plate assembly from an overhead
crane (lifting lug holes are provided) in prepara-
tion for mating to the pump housing.
36. Assemble one control link retainer ring (14, Fig-
ure 5-24) and one control link washer (15) onto
the threaded hole side of the control link pin
(16). Then thread a 1/4 in - 20 UNC capscrew
into pin to ease holding.
37. Carefully maneuver valve plate assembly, sup-
ported by overhead crane, over driveshaft and
into pump housing so slot on control piston (11)
engages control link (17).
38. With hole in control piston lined up with hole in
the link, carefully insert control link pin (16).
Care should be taken during this next step to prevent
the washer and retaining ring from falling into pump
housing.
39. Install second control link washer (15) and con-
trol link retaining ring (14) onto pin.
40. Once assembled, remove capscrew from pin.
NOTE: Valve plate is a slight press fit into pump
housing. Make sure pilot diameter on valve plate (17,
Figure 5-25) is aligned with mating diameter on the
pump housing prior to assembly.
41. Insert four capscrews (20, Figure 5-25) and
alternately tighten until valve plate is drawn up
to the pump housing. Tighten capscrews evenly
to 244 ft. lbs. (330 N.m) torque.
42. Install O-ring (22) with backup ring (23) in seal
groove of control cover cap (24).
43. Insert bias control piston springs (1, Figure 5-24)
into control piston (11). Use four capscrews (3,
Figure 5-25) to fasten control cover cap to back
of valve plate (17). Tighten capscrews (3)
evenly to 138 ft. lbs. (187 N.m) torque.
44. Install cover plate (19) with new O-ring (18) and
capscrews (21).
L05026