Hitachi EX20UR-2 Manual page 290

I
FRONT ATTACHMENT / Cylinder
1. Press bushing (13) in cylinder head (11).
IMPORTANT: After pressing in, be sure to con-
firm that the bushing surface is
flush with the bushing mount sur-
face in cylinder head (11). If there
is any difference in level between
bushing (13) and the bushing
mount in cylinder head (11), U-
ring (14) may be broken.
W506-0402-010
2. Install U-ring (14) in cylinder head (11).
IMPORTANT: Be sure to install U-ring (14) with
the lip side away from the bush-
ing, as illustrated.
VV506-04 -02 -011
3. Install wiper ring (12) in cylinder head (11) using
a pusher.
W04-02-20
Section a-a
Assemble Cylinders
Before assembling, clean components and parts with
cleaning oil and dry them completely. Apply clean
hydraulic oil to inner parts, sliding parts in particular,
before assembling.
After disassembling, always replace used wiper
rings, 0-rings, bushings, U-rings, backup rings, set
screws, and seal rings with new ones.