Loading ...
Loading ...
Loading ...
SERVICE
&
MAINTENANCE INSTRUCTIONS
HYDRAULIC VALVE REPAIR
(Figure
34)
Valve repair should be accomplished in a clean
work place. Individual components for many
of
the
assemblies are not available as repair parts. This
will simplify repair and allow you to replace
complete assemblies.
~
Pressure Settings on
ShocWDampenmg Valves
Pressure settings on shocWdampening valves are
preset at the factory. Although they are adjustable,
they must not be reset in the field using backhoe
hydraulic system. The backhoe pump will separate
or
crack
if
system pressure exceeds the maximum.
Relief valve adjustment requires
a
test bench and
accurate gauges.
Adjusting System Relief Valve
Pressure
Place a pressure gauge in the pump pressure line
at the relief valve. When installing pressure gauge,
be sure to use steel fittings that will withstand
working pressure up to
5000
psi. Remove cap nut
(6a). Adjusting screw (6c) has a hex socket
-
rotate
screw clockwise to increase pressure and
counter
-
clockwise to decrease pressure. Start
tractor PTO and set system relief valve pressure at
2000
psi. When pressure
is
adjusted, shut tractor
PTO
and
tractor
off.
Replace cap nut (6a) on
system valve.
Re lacing ShocWDarnpening
Va
P
ves
It is not necessary
to
remove console valve from
console to replace
shock/dampening valve
cartridges. Remove console cover and replace
them. Be sure you install valve cartridges set at the
correct pressure. Valves are similar and can be
easily mixed up.
.
ShocWDampening
Pressure
2
3500
PSI
.
4AA
4BB
2000
PSI
2500
PSI
5
2000
PSI
4cc
2500
PSI
Valve
Setting
Segment Replacement
1.
2.
3.
Relieve system pressure and remove valve
from backhoe. Remove tie rods and separate
the valve sections.
Replace defective sections as necessary.
Make sure you install
two
spacers between
each section of each tie rod. Note the location
of O
-
rings
(9
&
lo)..
They must be placed in
location between valve sections as shown.
When assembling valve sections, use care
when torquing nuts on tie rods. This must be
done in steps
-
that is to say, gradually
increasing the tightening torque up to
13
ft
-
lbs.
in an alternating sequence. Non
-
uniform
or
excessive tightening can cause binding of
spools. Failure to attain the proper torque can
result
in
leaks. Always use
a
torque wrench.
40
Loading ...
Loading ...
Loading ...