F. OVERLOAD PROTECTION
A relief valve must be installed in the system, unless it
is an integral part of the pump. The relief valve limits
pressure in the system to a prescribed maximum and
protects the components from excessive pressure. The
setting of the relief valve depends on the work
requirements of the system and the maximum pressure
ratings of the system components.
G. PORT POSITIONS
The pump cover can be assembled in four positions
with respect to the body. A letter in the model code (Table
II) identifies the cover position as shown in Figure 6.
Disassembly and assembly procedures are in Section VI-B
initially purge the air from the system. Failure to prime
within a reasonable length of time may result in damage
due to lack of lubrication. Inlet lines must be tight and free
from air leaks. However, it may be necessary to crack a
fitting on the outlet side of the pump to purge entrapped
With a minimum drive speed of 600 RPM, a pump should
prime almost immediately if provision is made to
Section V - SERVICE, INSPECTION AND MAINTENANCE
C. ADDING FLUID TO THE SYSTEM
A. SERVICE TOOLS
When hydraulic fluid is added to replenish the system, it
No special tools are required to service these pumps.
should always be poured through a fine wire screen - 200
mesh or finer. It is important that the fluid be clean and
free of any substance which could cause improper opera-
Periodic inspection of the fluid condition and tube or
tion or wear of the pump or other hydraulic units.
piping connections can save time-consuming breakdowns
Therefore, the use of cloth to strain the fluid should be
and unnecessary parts replacement. The following should
avoided to prevent lint getting into the system.
be checked regularly.
1. All hydraulic connections must be kept tight. A
loose connection in a pressure line will permit the fluid to
No periodic adjustments are required, other than to
leak out. If the fluid level becomes so low as to uncover
maintain proper shaft alignment with the driving medium.
the inlet pipe opening in the reservoir, extensive damage to
the pump can result. In suction or return lines, loose
connections permit air to be drawn into the systems,
Internal lubrication is provided by the fluid in the
resulting in noisy and/or erratic operation.
system. Lubrication of the shaft couplings should be as
2. Clean fluid is the best insurance for long service
specified by their manufacturers.
the reservoir should be checked
F. REPLACEMENT PARTS
If the fluid becomes contaminated the system should
Only genuine replacement parts manufactured or sold
be thoroughly drained and the reservoir cleaned before
by Vickers should be used. These are identified in the
new fluid is added.
parts catalogs listed in Table I.
Filter elements also should be checked and
replaced periodically. A clogged filter element results in a
Table IV lists the common difficulties experienced with
higher pressure drop. This can force particles through the
vane pumps and hydraulic systems. It also indicates the
filter which would ordinarily be trapped, or can cause the
probable causes and remedies for each of the troubles
by-pass to open, resulting in a partial or complete loss of
It should always be remembered that many apparent
pump failures are actually the failures of other parts of the
4. A pump which is running excessively hot or noisy is
The cause of improper operation is best
a potential failure. Should a pump become noisy or
diagnosed with adequate testing equipment and a thorough
overheated, the machine should be shut down immediately
understanding of the complete hydraulic system.
and the cause of improper operation corrected.