Komatsu 930E-2, Shop Manual

Page: 281 / 739

Assembly
NOTE: All parts must be completely dry and free of
foreign material. Lubricate all interior parts with clean
HYDRAIR
®
suspension oil (see Oil Specification un-
der “Oiling and Charging Procedure”).
Take care not to damage the machined or plated
surfaces, O-rings or seals when installing piston
assembly.
1. Install new rod seal (28, Figure 2-8), step seal
(27), and rod wiper (29).
When installing backup rings with rod seal (28)
and step seal (27), be certain radius is positioned
toward the seal and the white dot is positioned
away from the seal as shown in Figure 2-8.
2. Install new O-rings (22) and backup rings (23) in
their appropriate grooves in the bearing retainer
(18).
NOTE: Backup rings must be positioned toward bear-
ing retainer bolt flange as shown in Figure 2-9.
3. Install lower bearing (18) into lubricated suspen-
sion housing. Install capscrews and hardened
lockwashers (20 & 21) through bearing flange and
into tapped holes in housing. Tighten to 500 ft.
lbs. (678 N.m) torque.
4. Install new backup rings and O-rings (15, Figure
2-7) in end cap grooves. Backup rings must be
positioned toward the flange on the end cap.
5. Install new bearing (14) on upper bearing retainer
(5).
6. Slide upper bearing retainer assembly over cap
structure rod (16).
7. 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.
8. Attach a lifting device to top side of end cap
assembly. Lower assembly down on piston (7).
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.
9. Install upper bearing retainer (5) 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 housing in a
vertical position, carefully lower the piston rod and
end cap assembly into the bore of the cylinder
housing to its fully retracted position
11. Install capscrews and hardened washers (1 & 2)
and tighten to 500 ft. lbs. (678 N.m) torque.
12. Install bottom plug (19, Figure 2-8) and tighten to
13 ft. lbs. (17.5 N.m) torque.
NOTE: If suspension is to be stored, put in two pints
(1.0 l) of a rust preventive oil. This oil must be drained
when suspension is put into service.
13. Install charging valve and new O-ring (5, Figure
2-1). Lubricate O-rings with clean HYDRAIR
®
oil
before threading into end cap. Tighten large hex
of charging valve to 16.5 ft. lbs. (27.4 N.m) torque.
FIGURE 2-9. BACK-UP RING PLACEMENT
1. O-Ring
2. Backup Ring 3. Bearing Retainer
H02013 2/01 Front Suspensions H2-7