TM 55-4920-428-13
e. Remove pressure hose 145GS278-18 and return hose 145GS278-19 from the stowed position in-
side the hydraulic unit cover.
f. At the hydraulic unit, remove the RETURN connection cap and the return hose plug. Connect the
return hose to the RETURN connection. Connect the other end of the return hose to the return port of
the shop hydraulic power supply.
g. Remove the SUPPLY connection cap and the supply hose plug. Connect the supply hose to the
SUPPLY connection.
h. Connect the supply hose to the pressure port of the shop hydraulic power supply. The hydraulic
power supply line shall have a needle-type shutoff valve.
i. Connect the ELECTRICAL UNIT plug to the HYDRAULIC TEST SET receptacle. Connect the
HYDRAULIC UNIT plug to the ELECTRICAL TEST SET receptacle.
j. Check that the hydraulic unit valves and controls are set as follows:
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
CASE VENT LINE PRESS valve - Full CLOSE
RETURN BACK PRESS valve - Full CLOSE
LOW PRESS REGULATOR valve - Full DECREASE
RETURN SHUTOFF VALVE - Full OPEN
Both RETURN valves - OFF
Both SAS PRESS valves - OFF
Both ILCA PRESS valves - OFF
HIGH PRESS SHUTOFF VALVE - Full CLOSE
HIGH PRESS REGULATOR valve - Full DECREASE
(10) SOLENOID valve - CLOSED (in)
5-48. Solenoid Leak Test. Perform the test preparation (para 5-47), then proceed as follows:
a. Set the shop hydraulic power supply at to 2500 psi. Check that the power supply return and
pressure needle valves are open. (See fig. 2-6.)
b. The HIGH PRESS and LOW PRESS gages shall indicate 0 ± one scale division.
c. Set the HIGH PRESS REGULATOR to full INCREASE. Hold the pressure for 1 minute. There
shall be no increase in indicated pressures.
d. Set the HIGH PRESS REGULATOR to full DECREASE.
e. If no additional testing is required, reduce and shut off the shop hydraulic pressure.
5-49. Cycle Motor Operational Check. Perform the final test preparation (para 5-47), then proceed
as follows:
a. Set the electrical unit power switch to ON. The POWER light shall come ON.
b. Check that the CYCLE MOTOR switch is at OFF.
c. Check that the SOLENOID SHUTOFF switch is at CLOSED.
d. Set the CYCLE MOTOR switch to ON. The cycle motor link shall cycle.
e. Set the CYCLE MOTOR switch to OFF. The cycle motor shall stop.
f. If no additional testing is required perform the normal shutdown procedure (para 2-10).
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