( 1 ) The hydraulic pier supply (fig.. 134) consists of a
hydraulic fluid reservoir, a hydraulic
necessary. This filter contained within the
pump, and necessary line connections;
the oil reservoir Capacity is about 1
hydraulic actuator and may be removed
gallon. The pump is driven by a power
by removing the housing and screwing the
takeoff on the accessory drive.
filter out of the housing.
(2) Hydraulic power is supplied to the
(2) Clean the assembly with an approved
hydraulic throttle actuating unit where it is
solvent and dry thoroughly.
converted to useable control pressures.
(3) Inspect for cracks, breaks, leaks, freedom
The output pressure of the hydraulic
of movement of the linkage, and other
power supply is between BOO and 850
pounds per square inch with the engine
(4) Replace a damaged or defective actuator.
operating at rated -peed.
b. Cleaning and Inspection.
(1) Before installing the actuator, check the
(1) Periodically, check the oil level in the
force required to move the engine throttle
hydraulic power supply.
shaft. Any binding, sticking, or undue
(2) Change the hydraulic oil when it appears
friction will deteriorate the performance of
Replenish with MILL 0-5606
the electric governor.
hydraulic fluid or SAE 10 oil.
(2) After bolting the unit to the engine the
(3) Check condition of the hydraulic oil filter.
actuator piston is connected to the throttle
This is integral with the filter housing
or fuel rack linkage and adjusted so that
located in pressure port "P" of the
the actuator is able to move the fuel
To remove filter,
control from full closed to full open
unscrew fitting and lift out. If dirty, the
Proper governor operation
filter may be cleaned and re-inserted. Do
depends on correct adjustment of this
not operate governor without filters except
motion. In locking these adjustments,
in case of emergency.
extreme caution should be exercised to
(4) Check for low oil pressure. Insert a
prevent twisting the piston since a means
pressure gage (0-500 psi) in the oil line
has been included in the actuator to
running from the pressure port "P" of Me
prevent the piston from turning. Any twist
hydraulic supply to the pressure port "P"
introduced at the time of the connecting to
of the hydraulic actuator. With engine
the throttle linkage could place a side load
operating at rated speed (either under
on the mechanism and thereby add un-
manual or governor control), the output
pressure of the hydraulic power supply
installation, check actuator for free
should be 300-350 psi.
c. Removal and Installation
to figure 134
(3) The throttle position transducer located on
remove and install the components of the hydraulic
the actuator is factory aligned to the
piston travel, and, therefore, should not
need adjustment on a new installation.
93. Alignment of Electric Governor
92. Hydraulic System
a. General. The electric adjustments required at
installation are made with potentiometers listed below: