Potential Trouble
Servovalve does not follow input command
signal. (Actuator or components are
stationary or creeping slowly).
High threshold.(Jerky,possible oscillatory
or "hunting" motion in closed loop system).
Poor response. (Servovalve output lags
electrical command signal).
High null bias (High input current required
to maintain hydraulic cylinder or motor
stationary).
Probable Cause
1.Plugged inlet filter element
1.Plugged filter element
1.Partially plugged filter element
1.Incorrect null adjustment
2.Partially plugged filter element
Remedy
1.Replace filter element
1.Replace filter element
1.Replace filter element
1.Readjust null
2.Replace filter element and check for dirty
hydraulic fluid in system
7.TROUBLESHOOTING CHART
The following troubleshooting chart list potential troubles encountered,probable causes,and remedies.
8. FILTER ASSEMBLY REPLACEMENT
a. Remove the four socket head capscrews and lockwashers with 3mm Allen
wrench.
b. Remove the filter retainer.
c. Remove and discard the filter disk.
d. Remove and replace the O-Ring on the filter retainer and the O-Ring in
the filter bore.
e. Reinstall in reverse order,torque screws to 35-40 in-lbs.
9.AUTHORIZED REPAIR FACILITIES
Moog does not authorize any facilities other than Moog or Moog subsidiaries to
repair its servovalves.It is recommended you contact Moog at (716)655-3000
to locate your closest Moog repair facility.Repair by an independent
(unauthorized) repair house will result in voiding the Moog warranty and could
lead to performance degradation or safety problems.
Figure 3
O-Ring (Filter Disk)
O-Ring Retainer
Socket Head Screw (4)
Filter Disk
Filter Retainer
Lockwasher (4)
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