Hitachi Zaxis 330 Workshop Manual page 40

GENERAL / Precautions for Disassembling and Assembling
Floating Seal Precautions
1. In general, replace the floating seal with a new
one after disassembling.
If the floating seal is to be reused, follow these
procedures:
(1) Keep seal rings together as a matched set
with seal ring faces together. Insert a piece of
cardboard to protect surfaces. Apply oil to the
sliding surface (C) on seal ring (A).
(2) Check the slide surface (C) on seal ring (A) for
scuffing, scoring, corrosion, deformation or
uneven wear.
(3) Check O-ring
deformation or hardening.
2. If incorrectly assembled, oil leakage or damage
will occur. Be sure to do the following, to prevent
trouble.
(1) Clean the floating seal and seal mounting
bores with cleaning solvent.
Use a wire brush to remove mud, rust or dirt.
After cleaning, thoroughly dry parts with
compressed air.
(2) Clean the floating seal and seal mounting
bores. Check the bore surface for scuffing or
scoring by touching the surface.
(3) Check that the O-ring is not twisted, and that it
is installed correctly on the seal ring.
(4) After installing the floating seal, check that
seal ring surface (C) is parallel with seal
mating face (D) by measuring the distances
(C) and (D) at point (a) and (b), as illustrated.
If these distances differ, correct the O-ring
seating.
(B) for tears, breaks,
Correct
Incorrect
Correct
W1-1-4
A
B
Incorrect
D
a
C
b
a=b
a≠b
W105-03-05-019
W105-03-05-020
a
b
W110-03-05-004