SUBSECTION 5F
COUNTERBALANCE VALVES
NOTE
The counterbalance valve can be removed by reaching
down between the boom and right hand sidestand
from the shroud behind the operators cab.
2. Disconnect the pilot tube from the valve. Loosen the
capscrews which secure the inlet and outlet tube to the
valve. Tap the tubes gently to break the oil tight con-
nection. This will allow any trapped pressure to escape.
Then remove the capscrews and disconnect the inlet and
outlet tubes.
3. Remove the capscrews securing the counterbalance valve
mounting plate to the sidestand, and remove the valve.
4. Remove the mounting plate from the valve using a suit-
able Allen wrench.
Figure 5F-2. Counterbalance Valve Removal
REPAIR. Repair of this valve should be limited to the
replacement of O-ring seals and the parts in the poppet
subassembly. To replace these parts, proceed as follows:
Extreme caution must be exercised when removing
1. Place the valve in a vise with the cap end of the valve up.
the counterbalance valve from the machine. as this
Be sure the vise is equipped with protective jaws.
valve is the only hydraulic means of preventing the
boom from lowering once the boom has been ele-
2. Remove the four capscrews which secure the cap to the
vated. The following procedure describes a method of
valve body, and remove the cap (we Figure 5F-3).
removing the valve with the boom in the boom rest,
3. Remove the poppet subassembly from the valve body.
which is the preferred method. However, if circum-
stances do not allow removal of the counterbalance
4. Wash all the removed parts using a suitable cleaning
valve with the boom in the boom rest, a positive,
solvent.
mechanical means must be used to prevent boom
movement while repairing the counterbalance valve.
5. Inspect all the O-rings and wets on the poppet subas-
sembly, and replace any worn or damaged parts. The
poppet subassembly can be disassembled, by removing the
1. Lower the boom onto the boom rest, and secure it to
plug at the pilot end of the poppet subassembly.
the boom rest with the retaining pin.
Figure 5F-3. Counterbalance Valve (36Z683)
5F-3
