Section IV. HYDRAULIC SYSTEM
The hydraulic system is separated into three circuits which are used to operate the
services of the chassis, the A-frame and the launching equipment. Hydraulic fluid is
drawn from the PLS reservoir to the transmission-driven pump and directed through a
pressure filter to the control valves which operate the various hydraulic functions of
The hydraulic reservoir provides bulk storage of hydraulic fluid for operation of the
hydraulic circuits and is a modified version of the standard PLS reservoir.
A low-level warning switch is fitted to coincide with the minimum fluid level
(operational). A further low-level warning switch, coinciding with the minimum fluid
level (pump damage), stops the equipment functions should this level be reached.
These switches produce warning signals to the launch chest pack and the operators
interface control cabinet.
The temperature of the hydraulic fluid in the center of the reservoir is sensed by a
gauge thermometer probe device.
Hydraulic Test Points
Test points are fitted at strategic locations to assist monitoring and fault finding of the
hydraulic system. All test points can be used for hydraulic fluid sampling.
All hydraulic filters are equipped with an electrical indicator which signals filter
restrictions to the chest pack and operators interface control enclosure.