Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 660 / 1956

PAGE 10
Feb 28/07
3H20
29-10-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
C. Testing
(1) Normal Operation Test (See Figure 7.)
Connect the hydraulic pump into a system as shown in Figure 7 to check normal pump
operation. Maintain 27-28 VDC during all testing.
(a) Fill pump reservoir to full line (“F” mark on the reservoir) with clean filtered MIL-H-5606
hydraulic fluid. Ensure that pump vent is open (remove screw, washer and warning tag, if
installed). With the shut-off valve open, run the pump in the gear “UP” position for
approximately 10 seconds. Slowly close the valve to build up 50-100 psig, and bleed air
from the “UP” side of the system. Refill reservoir as required to keep fluid level between
“F” and “L” marks during all testing.
NOTE: Do not overfill. Add fluid only when level falls below the “L” mark. When filling,
allow fluid level to stabilize before comparing fluid level to fill marks. Overfilling
will result in excess fluid being expelled from reservoir vent pipe.
(b) With the shut-off valve in the open position, apply power to the pump with the gear switch
in the gear “UP” position. Allow the pump to operate approximately 15 seconds. Slowly
close the shut-off valve. The pressure switch shall turn the pump off at 1400 psig
maximum. Continue to supply electrical power to the pump and observe for pressure drop
and no pump operation for 5 minutes. Except, if the pump operates once momentarily
during this five minute period there shall be no repeated pump operation during the
subsequent fifteen minutes.
(c) Repeat (b), above, with the gear switch in the gear “DOWN” position.
(d) With the shut-off valve open, the gear selector switch in the gear “DOWN” position and the
pressure switch disconnect switch in the “DOWN” position, allow the pump to operate
approximately 10 seconds. Slowly close the shut-off valve. Observe the maximum
pressure indicated and immediately shut pump off. The maximum pressure shall be at
least 1550 psig but not more than 1800 psig. With the pump off observe that the pressure
does not fall below 1350 psig in 5 minutes.
(e) Repeat (4), above, with the gear switch and pressure switch disconnect switch in the gear
“UP” position. The maximum pressure shall be at least 1550 psig but not more than 2000
psig.
NOTE: If pump is not installed in an aircraft, reinstall vent screw, washer, and warning
tag upon completion of test.
(2) Thermal Relief Valve Operation Test
(a) Fill pump reservoir to full line (“F” mark on the reservoir) with clean filtered MIL-H-5606
hydraulic fluid. Ensure that pump vent is open (remove screw, washer and warning tag, if
installed).
(b) With a suitable pump and calibrated gauge, slowly apply hydraulic pressure individually to
the pump “UP” and “DOWN” outlet ports. The first indication of pressure relief shall occur
at 2450 to 2600 psig for both “UP” and “DOWN” sides of the pump assembly.
NOTE: If pump is not installed in an aircraft, reinstall vent screw, washer, and warning
tag upon completion of test.