(11)
Put the system No. 4 TAIL FLT CONTROL SHUTOFF switch on the P461 overhead maintenance panel in the ON position.
S 866-229
(12)
Make sure that the handle for the landing gear selector on the P2 first officer's panel is in the OFF position.
S 866-230
(13)
Put the system No. 4 HYD PUMPS ENG switch on the P5 overhead panel in the ON position.
F.
Hydraulic System No. 4 - Total Internal Leakage Check
S 866-231
(1) Pressurize hydraulic system No. 4 to 3000 psig.
S 866-453
WARNING: MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF THE LE AND TE
_______ FLAPS AND FLAP DRIVE MECHANISMS BEFORE YOU MOVE THE FLAP CONTROL LEVER. WITH HYDRAULIC POWER REMOVED, THE FLAPS WILL MOVE AUTOMATICALLY BY ELECTRICAL POWER WHEN YOU MOVE THE FLAP CONTROL LEVER.
(2)
Operate the flight controls through four or five cycles.
S 866-454
(3)
Operate the outboard flaps through 3 full cycles.
(4)
Make sure the flight controls are in the center position.
(5)
Make sure the flap control handle is in the "0" detent position.
S 976-233
(6)
Let the flow become stable for 3 minutes and write this flow as flow
S 866-455
S 866-671
No. 1. Flow No. 1__________GPM
If the internal leakage of system No. 4 (Flow No. 1) is more than 5 GPM, you must complete the remainder of this test.
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29-11-00
ALL ú ú 01 Page 664 ú Feb 15/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
G. Hydraulic System No. 4 - Pressure Module Check
S 796-234
(1) Examine the system No. 4 auxiliary pump for mechanical vibration and noise.
NOTE: This is an indication of flow or pump rotation.
____
S 426-456
(2)
If there is a sign of flow to the auxiliary pump through its pressure hose, replace the check valve for the auxiliary pump in the pressure module (AMM 29-11-23/201).
S 796-235
(3)
If the hydraulic service cart is used as a pressure source, monitor the HYD PUMPS DEMAND PRESS and HYD PUMPS ENGINE PRESS lights on the P5 overhead panel.
S 216-673
(4)
If the demand pump is used as a pressure source, monitor the HYD PUMPS ENGINE PRESS light.
S 966-674
(5)
If one of the lights that is monitored goes off, replace the applicable check valve in the pressure module (AMM 29-11-23/201).
S 796-236
(6)
Carefully feel the return line between the pressure module and the reservoir.
(a)
If the return line is hot, replace the pressure relief valve in the pressure module (AMM 29-11-23/201).
H.
Outboard Trailing Edge Flap Control System - Internal Leakage Check
(1)
Put the ALTN FLAPS arming switch in the ARM position.
S 976-238
(2)
Let the flow become stable for one minute and write this flow as
S 866-237
flow No. 2. Flow No. 2__________GPM
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29-11-00
ALL ú ú 01 Page 665 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
S 976-239
(3) Subtract flow No. 2 from flow No. 1 and write this flow as flow
No. 2A. Flow No. 1__________GPM Flow No. 2__________GPM
Flow No. 2A__________GPM
NOTE: Flow No. 2A is the null leakage of the motor for the
____
outboard trailing edge flap.
S 866-240
(4)
Put the control handle for the trailing edge flap in the 10 unit detent.
S 976-241
(5)
Let this flow become stable for one minute and write this flow as
flow No. 3. Flow No. 3__________GPM
S 976-242
(6) Subtract flow No. 3 from flow No. 2 and write this flow as flow
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