Komatsu PC200-8M0 Shop Manual page 1107

500 Hydraulic system
Disassembly and assembly of work equipment cylinder
a Fully tighten piston assembly (4) until
it contacts with end face (b) of the
rod. Then, at around this position,
align screw holes (H) in the piston
and piston rod end face.
a For a cylinder with a head cushion,
ensure that there is a small play in
plunger (5) with piston assembly (4)
installed.
q Only the boom and arm cylinders
2) Install screw (3) to lock piston assembly
(4) and piston rod assembly (2).
2
Screw (3) thread portion:
3
Screw (3):
58.9 – 73.6 Nm {6 – 7.5 kgm}
a After installing screw (3), caulk the
screw at four peripheral places (a).
7. When replacing either or both of piston rod
assembly (2) and piston assembly (4) with new
ones, assemble the new ones according to the
following procedure.
1) Using tool U2, screw in piston assembly
(4) until it comes into contact with end face
(b) of the rod.
a If the cylinder has the bottom cushion,
put a mark on the rod end face to indi-
cate the tightening position of the ball
cap.
PC200, 200LC, 220, 220LC-8M0
Adhesive (Loctite #262)
3
Piston assembly (4):
294 ± 29.4 Nm {30 ± 3.0 kgm}
a For a cylinder with a head cushion,
ensure that there is a little play in
plunger (5) with piston assembly (4)
installed.
Only the boom and arm cylinders
q
2) Drill a screw hole across the threads of
piston rod assembly (2) and piston assem-
bly (4).
a With a drill aligned with the V groove
where the threads of piston assembly
(4) and piston rod assembly (2) are
mated, drill a hole straight.
a The cylinder with the bottom cushion
must not be machined in the cushion
cap machining hole position.
q Dimensions of screw hole (mm):
Tap drill diameter
Tap drill hole
depth
Screw hole size
Screw hole depth
a After tapping the screw hole, remove
chips and other dirt and thoroughly
clean the area.
SEN06146-00
10.3
27
12 x 1.75
20
33
50-500