Service Manual
IO
SPRING
TENSION ADJUSTER
(IMPLEMENT CIRCUIT PRESSURE)
FIG.
7.
Implement Relief Valve Removed
(
108494/
109679
Va Ives)
5.
Remove the bolts securing the valve together.
Separate the sections one at a time, carefully
noting the location and quantity of mylar shims
around the bolt holes (if used).
CHECK FOR
SHIMS
FIG.
8.
Separate Valve Sections
6.
Remove and discard the O-rings and shims from
each section. Thoroughly clean and inspect all
parts. Generally, any deep scratches or scoring
of
the spool valve or bore, or other visible
damage will make the valve unserviceable.
FIG. 9.
Single Valve Disassembled
3-
FIG.
10.
Double Valve Disassembled
7.
Reassemble the valve in reverse order, using
the new parts supplied in the overhaul kit. The
following assembly notes apply:
a. Use care not to pinch O-rings between sec-
tions. Torque bolts to
72-75
in. Ibs.
b.
Install an O-ring in valve body. Insert spool
valve from spool cap end, then install valve
handle.
c.
Install an O-ring in the groove at the spool
cap end
of
the valve body.
If
the valve was
made before
6-75
(see "Manufacturing Date
Code"), use the special oversize O-ring,
which
is
slightly thicker than the standard
ring.
d. When securing the shoulder screw (Fig.
5),
be sure the shoulder passes through the
center of the special washer, or the spool
valve will operate in only one direction.
e. The float detent, on valves
so
equipped
(Fig.
5B),
is
adjusted using the set screw on
the bottom of the valve. Properly adjusted,
the spool valve
will
lock into the float posi-
tion when engaged, yet release easily when
light
pressure
is
applied to the handle.
VALVE
DESCRIPTION
(VICTOR)
The hydraulic control valves are made up
of
one
or two spool valves and a cast iron valve body.
Normal working pressure
is
500-700
PSI.
An imple-
ment relief valve
is
part of the control valve and
is
factory set at
700
PSI
-
do not attempt
to
alter this
setting. Severe transmission damage may
result.
Refer
to the applicable repair manual for system pressure
tests and adjustments.
There are two ports for each spool. When spool
is
moved into valve, one port
is
pressurized and one port
becomes an outlet. When spool
is
moved out of valve,
ports are reversed.
Spool
valve
is
spring loaded to
return to a middle, "neutral" position, where both
lift
cylinder ports are sealed
off
from the pressure and
outlet ports. These are open-center valves,
so
hydraulic
oil
is
free to flow from the pressure port to the outlet
port when the spool
is
in neutral. Attachment float
is
accomplished mechanically by the tractor's
lift
link-
age, or through a detented
float
position provided on
one spool of the two-spool control valve.