7-23
4. TRAVEL MOTOR
The followings are the general maintenance standards. However, it is the most important to
determine which parts should be replaced, depending on the characteristics before disassembling,
damages and discoloration of exterior view, the purpose of disassembling, the expected remaining
service life. etc..
Check item
Sliding surface of
cylinder block,
valve plate and
swash plate
Clearance
between piston
and cylinder block
Play between pis-
ton and shoe
Measuring method
Criteria
Allowable
Remedy
Surface roughness of
cylinder block, valve
plate and swas plate
Swash plate
- hardness of sliding
surface
Outer dia of piston
d max - d min
Inner dia of
cylinder bore
D max - D min
Clearance D-d
Play between calked
piston and shoe (
ɺ
)
Measure the surface
roughness by rough-
ness tester
Measure the surface
hardness of swash
plate by hardness tes-
ter
Measure outer dia of
piston and bore of
cylinder block at least 3
places in the longitudinal
direction with microme-
ter and obtain :
max outer dia = d max
min outer dia = d min
max inner dia = D max
min inner dia = D min
With the jig, hold down
the shoe on work stand
and pull up the piston
vertical direction to
measure the play
between piston and
shoe
Below
0.4 Z
ʂ
Over HS78
0.01 mm
0.01 mm
0.037~
0.047 mm
0~0.1 mm
Below
3.0 Z
ʂ
HS74
0.05 mm
0.022 mm
0.065 mm
0.3 mm
Replace or repair
侍
Lap together
the surfaces of
both cylinder
block and valve
plate to remedy
their roughness
(# 1200 power)
Replace
Replace piston or
cylinder block
侍
In exchanging
pistons, replace
all of nine pis-
t o n s a t t h e
same time
Replace piston
D
d
Measurement
position
Magnet
stand
Work
stand
Dial gauge
Piston
Jig
Shoe
85
34
+0.1
+0.2
43
32
26
Play
Method
Jig for measuring play
ɺ
29097MS10
