13
Section V
–
Service and Maintenance
A. Service Tools
No special tools are required to service CM2 or CM3 series
multiple unit valves.
B. Inspection
Periodic inspection of spool operation, oil condition and
pressure connections saves time-consuming breakdowns
and unnecessary parts replacement.
1. All hydraulic connections must be kept tight. Loose
connections not only allow leakage but also permit air to be
drawn into the system, resulting in noisy and/or erratic
operation.
2. Spools should return to neutral automatically when
the control is released. The centering spring force is approxi-
mately 60 to 120 pounds. If more force is necessary, the
spool may be binding or control linkage may be faulty.
3. System filters and reservoir should be checked
periodically for foreign particles. If excessive contamination
is found, the system should be drained. The reservoir must
be cleaned thoroughly before refilling.
C. Adding Fluid to the System
When hydraulic fluid is added to the system, it should be
pumped through a 25 micron filter. If such a filter is not avail-
able, or practical to use in the field, a funnel with a fine wire
screen (200 mesh or better) can be used.
It is important that oil be clean and free of all substance
which will cause improper operation and excessive wear of
the pump or other hydraulic units in the system. Be sure to
purge all air from the system.
D. Lubrication
Internal lubrication is provided by system oil.
E. Replacement Parts
Only genuine parts manufactured or sold by Vickers should
be used as replacement parts for these valves. Only Vickers
knows the true quality level required of each part. These are
listed in parts catalogs M-2401-S, M-2402-S, M-2403-S and
M-2404-S copies of which are available on request.
