Filter
Top Products
60
Hydraulic
System
Tractors,
Lawn
and
Garden
-
110
and
112
5-4
General
Information
SM-2059-(Apr-67)
SYSTEM
ANALYSIS
Here
are
three
of
the
most
common
com-
plaints
connected
with
the
hydrauli
c
syst
e
m.
Howev
e
r,
before
servicing
the
system,
be
sur
e
to
check
pa
ges
5-6
and
5-7
for
diagnosing
oth
e r
hydraulic
system
malfunctions.
OIL
LEAKAGE
A
slight
amount
of
oil
leakage
below
the
con-
trol
valve
and
pump
is
considered
normal.
Ad-
vise
customer
to
ignore
this
condition
except
to
wipe
these
areas
oc
casionally
to
prevent
ac-
cumula
tion
of
dust
and
dirt
above
the
engine.
If
excessive
leakage
seems
to
be
caused
by
oil
spewing
out
the
filler-vent
plug
on
the
res-
ervoir,
especially
on
112H
Tractors
(
-6727),
a
baffle
plate
can
be
installed
on
the
pump
back
plate.
See
page
15-3.
r
II
Fig.
4-Faulty
O·Rings
Causing
Oil
Le
a
kage
Leakage
can
also
be
caused
by
O-rings
which
are
worn,
damaged
or
have
paint
on
them,
Fig-
ure
4.
LOSS
OF
HYDRAULIC
PRESSURE
Loss
of
hydraulic
pressure
and
failure
to
lift
ca n
be
caused
by
a s
cored
diaphragm
or
pump
body
probably
caused
by co
ntaminated
oil.
Bod
y
wear
and
loss
of
pr
es s
ure
also
can
be
caused
by
prolonged
periods
of
operation
with
exc
ess
ive
drive
belt
tension
.
Ex
c
essive
belt
tension
caus
es
rapid
bearing
wear
which
allows
the
pump
gears
to
contact
and
wear
the
body.
Cavitation,
foam-
in
g
oil
or
slow
hydraulic
lift
operation
may
in-
di
ca
te
a
scored
body.
Loss
of
hydraulic
pressure
also
can
be
caused
by
normal
wear
of
the
pump
gear
teeth.
This
con-
dition
can
be
detected
by
slow
operation
of
the
hy
draulic
lift,
cavitation
or
foaming
o
il.
ERRATIC
LIFT
OPERATION
I
.
~
.
Fig.
6-Marred
or
Scratched
Lift
Check
Plunger
Cau
s
es
Lood
to
Lower
Whe
n
Lift
Lt
' ve r
is
Raised
Scratched
or
pitted
surfaces
on
lift
check
plunger
and
seat
will
allow
work
load
to
lower
when
spool
is
in
slow
raise
position.
Weak
or
broken
centering
spool
springs
can
also
cause
the
spool
to
move
out
of
position.
This
causes
self-actuation
of
the
control
valve.
Check
the
spool
springs
when
lift
lever
action
seems
to
be
sluggish.
Also
check
lif~
lever
stop
adjustment,
page
15-9.
When
the
workload
drops
for
no
apparent
rea-
son,
check
for
oil
around
the
cylinder
connec-
tions,
If
connections
are
not
losing
oil,
the
pis-
ton
O-ring
may
be
leaking.
The
hydraulic
cyl-
inder
is
not
serviceable
and
must
be
replaced
when
found
defective.
Fig.
5-Defective
Pump
Diaphragm
and
Pu
mp
Bady
Litho
in
U.S.A.