(a)  
Clean the drain line with the solvent.

(b)  
Dry the drain line with the compressed air.

(3)  
If the parts for the fuel drain housing have carbon material, clean the parts for the fuel drain housing:

(a)  
Clean the upper drain housing, spring, screen and lower drain housing with solvent.

(b)  
Dry the parts with compressed air.

(4)  
If there is blockage in the drain reducer on the combustion chamber cap or in the turbine plenum boss, remove the blockage:

(a)  
Remove the combustor unit (AMM 49-31-42/401).

(b)  
Use the vacuum cleaner to remove the blockage from the inside of the combustion chamber cap or the turbine plenum.

(5)  
If there is carbon material in the drain reducer on the combustion chamber cap or in the turbine plenum boss, clean the drain reducer or turbine plenum boss:

(a)  
If it is not already done, remove the combustor unit (AMM 49-31-42/401).

(b)  
Clean the drain reducer and turbine plenum boss with the solvent.

1)  If you must disassemble the combustor unit to remove the carbon material, install a new combustor unit (AMM 49-31-42/401).
(6) If the combustor unit was removed, install the combustor unit (AMM 49-31-42/401).
E.  Install the fuel drain housing to the turbine plenum:
(1)  
Apply a layer of the antiseize compound to the threads of the upper drain housing.

(2)  
Install a new packing on the upper drain housing.

(3)  
Install the upper drain housing to the turbine plenum boss.

(4)  
Tighten the upper drain housing to 270 pound-inches (30.5 newton-meters).

(5)  
Put the screen and spring in the lower drain housing.

(6)  
Install a new packing on the lower drain housing.

(7)  
Install the lower drain housing to the upper drain housing with the clamp.

NOTE: Do not tighten the clamp at this time.

(8)  
Install the drain seal to the lower drain housing.

504 
Aug 01/94  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  49-31-71 Page 605 

F.  Install the drain line:
(1)  
Apply a layer of the antiseize compound to the threads of the drain reducer, drain union and drain line.

(2)  
Connect the drain line to the drain reducer on the combustion chamber cap.

(3)  
Connect the drain line to the drain union on the fuel drain housing.

(4)  
Tighten the drain reducer, drain union and drain line to 270 pound-inches (30.5 newton-meters).

G.  Tighten the clamp on the fuel drain housing until the lower drain housing does not turn.
504 
49-31-71 Page 606  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Feb 01/95 

HIGH PRESSURE FUEL FILTER - SERVICING
1.  General
A.  The high pressure fuel filter element is a micronic filter which filters fuel passing from the pump to the governor of the fuel control unit.
2.  Equipment and Materials
A.  Cleaning Solvent - Federal Specification P-D-680
B.  Lubricating Oil - MIL-L-6081
3.  High Pressure Fuel Filter Servicing (Fig. 301)
A.  Unscrew filter cap from fuel control unit.
B.  Remove filter element and packing.
CAUTION:  EXERCISE EXTREME CARE TO PREVENT ANY DIRT FROM ENTERING FUEL CONTROL UNIT.
C.  Clean filter cap in solvent and dry thoroughly.
WARNING:  SOLVENT IS TOXIC. USE IN WELL-VENTILATED AREA. KEEP AWAY FROM FLAME.
D.  Lubricate and install new packing in filter element.
E.  Install new filter element with packing over filter guide. Lubricate and install new packing on filter cap.
F.  Install filter cap in fuel control unit, tighten to torque value of 100 to 120 pound-inches.
G.  Safety wire filter cap to fuel control unit housing.
H.  APUs WITH ALLIEDSIGNAL SB GTCP85-49-7096; examine the high pressure fuel filter for leakage:
(1)  
Start and operate the APU (AMM 49-11-0/201).

(2)  
During the APU operation, examine the high-pressure fuel filter for leakage.

(3)  
Do the APU normal shutdown (AMM 49-11-0/201).

(4)  
Attach a DO-NOT-OPERATE tag to the APU master switch on the P5 forward overhead panel.

(5)  
If you found leakage, repair the cause of it.

I.  APUs WITHOUT ALLIEDSIGNAL SB GTCP85-49-7096; examine the high pressure fuel filter for leakage:
(1)  
Start and operate the APU (AMM 49-11-0/201).
　
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