(2)
Access Panels
317AL APU Access Door - Left
318AR APU Access Door - Right
E.
Procedure
S 424-030
CAUTION: REMOVE THE PROTECTION COVERS FROM THE OPENINGS AS NECESSARY.
_______ IF YOU DO NOT REMOVE THE PROTECTION COVERS, DAMAGE TO THE APU CAN OCCUR.
(1)
Do these steps to install the air-cooled oil cooler (4):
(a)
Put the clamp (1) loosely over the flange of the cooling air outlet duct.
(b)
Lubricate the four new packings (5) with a light coat of oil.
(c)
Install the four packings (5) on the two transfer tubes (6).
(d)
Install the two transfer tubes (6) in the oil supply and return ports of the air-cooled oil cooler.
(e)
While you install the air-cooled oil cooler (4) on the load gearbox, make sure the two transfer tubes (6) are installed in the correct positions on the load gearbox.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
49-91-01
ALL ú ú 02 Page 404 ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
(f)
Install the air-cooled oil cooler (4) on the load gearbox with the four washers (2) and four nuts (3). 1) Tighten the four nuts (3) to 75-85 inch-pounds (8.5-9.6
newton-meters).
(g)
Put the cooling air outlet duct and clamp (1) on the flange of the air-cooled oil cooler (4). 1) Tighten the clamp (1) to 12-18 inch-pounds (1.4-2.0
newton-meters).
F. Air-Cooled Oil Cooler Installation Test
S 864-020
(1)
Remove the DO-NOT-CLOSE tags and close these circuit breakers:
(a)
P6-2 Main Power Distribution Panel
1) 6K18, APU ALTN CONT
(b)
P83 Aft APU Equipment Control and Circuit Breaker Panel 1) APU PRIME CONT
S 864-021
(2)
Remove the DO-NOT-OPERATE tag from the APU control switch on the P5 overhead panel.
S 794-022
(3)
Do the installation test for the air-cooled oil cooler:
(a)
Do this task: APU Starting and Operation (AMM 49-11-00/201).
(b)
Operate the APU for a minimum of five minutes.
(c)
During the APU operation, examine the air-cooled oil cooler for signs of oil leakage.
(d)
If you find oil leakage, then do these steps to repair the leakage: 1) Do this task: APU Usual Shutdown (AMM 49-11-00/201). 2) Attach a DO-NOT-OPERATE tag to the APU control switch on
the P5 overhead panel. 3) Repair the cause of the oil leakage. 4) Remove the DO.NOT.OPERATE tag from the APU control switch
on the P5 overhead panel. 5) Do this task: APU Starting and Operation (AMM 49-11-00/201). 6) During the APU operation, examine the air-cooled oil cooler for signs of oil leakage. 7) If you find oil leakage, do the leakage repair again.
(e) If it is not necessary to do other tasks, do this task: APU Usual Shutdown (AMM 49-11-00/201).
S 614-033
(4) Make sure the APU oil system is full. To check the oil level, do this task: APU Oil Tank Replenishing (AMM 12-13-02/301).
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
49-91-01
ALL ú ú 01 Page 405 ú Oct 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
G. Put the Airplane Back to Its Usual Condition
S 414-032
(1)
Close the left APU access door, 317AL, and right APU access door, 318AR:
(a)
Remove the two quick-release pins, disconnect the two hold-open rods and put the two hold-open rods in the two clips on the right access door.
(b)
Install the two quick-release pins in the two brackets on the right APU compartment bulkhead.
(c)
Lift the right access door until you can install the lanyard on the pin at the aft APU compartment bulkhead.
