Assembly - Komatsu 830E Shop Manual

Assembly

NOTE: All parts must be completely dry and free of for-
eign material. Lubricate all interior parts with clean
®
HYDRAIR suspension oil (see Oil Specification under
"Oiling and Charging Procedure").
Take care not to damage the machined or plated
surfaces, O-rings or seals when installing piston
assembly.
When installing backup rings with rod lip seal (25)
and buffer seal (24), be certain radius is positioned
toward the seal as shown in Figure 2-8.
1. Install new rod buffer seal (24, Figure 2-8), lip
seal (25), and rod wiper (26).
2. Install new O-rings (20) and backup rings (21) in
their appropriate grooves in the bearing structure
(16).
NOTE: Backup rings must be positioned toward bear-
ing retainer bolt flange as shown in Figure 2-9.
FIGURE 2-9. BACKUP RING PLACEMENT
1. O-Ring
2. Backup Ring
3. Install lower bearing assembly (16) into lubricated
suspension housing. Install capscrews and hard-
ened lockwashers (18 & 19) through retainer
flange and into tapped holes in housing. Tighten
to 310 ft. lbs. (420 N.m) torque.
H02016
3. Bearing Structure
Front Suspensions
4. Install new backup rings and O-rings (14 & 15,
Figure 2-7) in end cap grooves. Backup rings
must be positioned toward the flange on the end
cap.
5. Slide upper bearing structure (6) over cap struc-
ture rod.
6. Install key (13) and piston stop (12) on cap struc-
ture rod. Make sure piston stop is fully seated
against the rod shoulder. Install locknut (11)
against piston stop. Tighten locknut one half turn
further, until hole for the roll pin (10) is in align-
ment. Install roll pin.
7. Attach a lifting device to top side of end cap
assembly. Lower assembly down on piston (8).
Insert steel balls (9) in holes in piston prior to fully
seating bearing on top of piston. A small amount
of petroleum jelly will prevent the balls from drop-
ping out during assembly.
8. Install upper bearing structure (6) onto piston rod.
Secure bearing in place with NEW capscrews (3)
and hardened washers (4). Tighten capscrews to
500 ft. lbs. (678 N.m) torque.
NOTE: ALWAYS use new capscrews (3, Figure 2-7)
during assembly. Used capscrews will be stressed and
fatigued because of loads imposed on these cap-
screws during operation.
10. Apply a light coating of petroleum jelly to the
seals, wiper and bearings. With suspension hous-
ing in a vertical position, carefully lower the piston
rod and end cap assembly into the bore of the cyl-
inder housing to its fully retracted position
11. Install capscrews and hardened washers (1 & 2)
and tighten to 310 ft. lbs. (420 N.m) torque.
12. Install bottom plug (17, Figure 2-6) and tighten to
13 ft. lbs. (17.5 N.m) torque.
13. Install charging valve (5, Figure 2-1) using a new
flat gasket under the large hex (valve body).
Tighten large hex of charging valve to 16.5 ft. lbs.
(27.4 N.m) torque.
14. Install remaining plugs and/or pressure sensor.
15. Pressure test according to instructions on the fol-
lowing page.
H2-7