TM 1-1520-238-T-5
7–64
Change 2
7–10.
PRIMARY HYDRAULIC SYSTEM – MAINTENANCE OPERATIONAL CHECK (cont)
7–10
Task
Result
ae. Subtract measurement A from B. Cylinder
travel is 1.564 to 1.624 inches.
If cylinder travels full stroke, go to step am.
af. Check servocylinders for fluid leakage
(TM 1-1520-238-23).
If leakage is present, replace leaking servocylinder
(TM 1-1520-238-23).
ag. Disconnect push–pull rod from servocylinder
valve arm (TM 1-1520-238-23).
ah. Slowly push servocylinder valve arm upward
to fully retract piston.
ai. Have assistant measure and record cylinder
stroke with inside calipers. Measurement A
is from bottom of jam nut to top surface of
servocylinder housing (cylinder retracted).
aj. Slowly pull servocylinder valve arm
downward to fully extend piston.
ak. Have assistant measure and record cylinder
stroke with inside calipers. Measurement B
is from bottom of the jam nut to top surface
of the servocylinder housing (cylinder
extended).
al. Subtract measurement A from B. Directional
travel is 1.564 to 1.624 inches. All other
cylinders travel is 3.500 to 3.560 inches.
If cylinder does not travel full stroke, replace
servocylinder (TM 1-1520-238-23).
If cylinder travels full stroke, perform appropriate flight
control system rigging check (TM 1-1520-238-T-7).
am. Disconnect and remove AGPU hydraulic
pressure from helicopter
(TM 1-1520-238-23).
an. Start helicopter APU (TM 1-1520-238-23).
ao. Check that PRI HYD indicator (fig. 7–25)
indicates 3000 PSI.
If 3000 PSI is not indicated, go to paragraph 7–20.
ap. Shutdown APU (TM 1-1520-238-23).
9. Remove external power – electrical (TM 1-1520-238-23).
10. Disconnect maintenance headset (TM 1-1520-238-T-4).
11. Close and secure all access panel and doors opened during this maintenance operational check
(TM 1-1520-238-23).
END OF TASK
