Maintenance & Repair Manual
SECTION 3
VIRTUOSO 5460P
28
110057 REV K
3.14 Hydraulic Valves
The hydraulic valves are located inside the right-hand machinery cabinet, and can be
accessed through the outer access panel or through the top of the machinery cabinet.
See Section 3.3 for instructions on opening the machinery cabinet from the top.
Refer to the following instructions for adjusting or removing any of the four components
located in the manifold. It is recommended that you place paper towels below the
component to be removed to catch the several ounces of hydraulic fluid that will drip
from the manifold as the component is removed. Refer to the figure on the following
page for component identification.
•
Counterbalance Valve: If the lift car "bounces" as it descends while fully loaded, then
the adjustment screw on this valve may need to be tightened. To do so, loosen the
lock nut using a 1/2" wrench, turn the adjustment screw clockwise 1/4 turn using a
5/32" hex key, and then retighten the lock nut. Test and repeat as necessary until
the "bouncing" has been eliminated. To remove this valve, use a 7/8" wrench.
When reinstalling the counterbalance valve, torque it to 18.5-22.0 ft-lbs.
•
Check Valve: This valve cannot be adjusted. Use a 7/8" wrench to remove the valve
from the manifold. When reinstalling the check valve, torque it to 25-30 ft-lbs.
•
Directional Valve: This valve cannot be adjusted. This valve can be removed while
the lift car is not at the lower landing provided that the counterbalance valve is
working correctly. However, if the lift car starts to descend while you are turning this
valve out of the manifold, immediately tighten the valve back into the manifold; the
counterbalance valve is malfunctioning and must be replaced (with the lift car at the
lower landing). Before removing this valve, pull the electrical harness connectors off
of the coil terminals. Then remove the black button by turning it counterclockwise,
WARNING!
The lift car MUST be either at the lower landing or secured in place before the
COUNTERBALANCE VALVE or CHECK VALVE is loosened or removed.
Failure to do so could result in the lift car dropping and/or high pressure
hydraulic oil leaks.
