(a)  
Clean the drain line with the solvent.

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

(3)  
If the drain tee has blockage, remove the blockage with the compressed air.

(4)  
If the drain tee has carbon material, clean the drain tee:

(a)  
Clean the drain tee with the solvent.

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

504 
Aug 01/94  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  49-31-71 Page 601 

A33436 A33626
Fuel Drain - Inspection/Check  501 
49-31-71  Figure 601 (Sheet 1)  Jun 20/92 
Page 602 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

501  Fuel Drain - Inspection/Check 
Aug 01/94  Figure 601 (Sheet 2)  49-31-71 
Page 603 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

(5)  
If there is blockage in the drain union on the combustion chamber cap or in the plenum union on the turbine plenum, 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.

(6)  
If there is carbon material in the drain union on the combustion chamber cap or in the plenum union on the turbine plenum, clean the drain union or plenum union.

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

(b)  
Clean the drain union and plenum union 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).
(7)  If the combustor unit was removed, install the combustor unit (AMM\49-31-42/401).
E.  Install the drain tee to the plenum union on the turbine plenum.
(1)  Make sure the position of the drain union on the drain tee points in the direction of the drain union on the combustion chamber cap.
F.  Install the drain line:
(1)  
Connect the drain line to the drain union on the combustor chamber cap.

(2)  
Connect the drain line to the drain tee.

4.  Fuel Drain Inspection (APUs with the Fuel Drain Housing) (Fig. 601)
A.  Remove the drain line:
(1)  
Disconnect the drain line from the drain union on the fuel drain housing.

(2)  
Disconnect the drain line from the drain reducer on the combustion chamber cap.

(3)  
Remove the drain line from the APU.

B.  Remove the fuel drain housing from the turbine plenum:
(1)  
Remove the drain seal from the lower drain housing.

(2)  
Remove the clamp that holds the lower drain housing to the upper drain housing.

(3)  
Remove the lower drain housing from the upper drain housing.

(4)  
Remove the spring, screen, and packing from the lower drain housing.

(a)  Discard the packing.

(5)  
Remove the upper drain housing from the turbine plenum boss.

(6)  
Remove the packing from the upper drain housing.

(a)  Discard the packing.
C.  Do an inspection of the fuel drain:
(1)  
Make sure the drain line has no carbon material or blockage.

(2)  
Make sure the parts for the fuel drain housing have no carbon material.

(3)  
Make sure the drain reducer on the combustion chamber cap has no carbon material or blockage.

(4)  
Make sure the turbine plenum boss has no carbon material or blockage.

504 
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D.  If there is carbon material or blockage in the fuel drain, clean the applicable parts:
CAUTION:  DO NOT GET THE SOLVENT IN YOUR MOUTH, OR YOUR EYES, OR ON YOUR SKIN. DO NOT BREATHE THE FUMES FROM THE SOLVENT. PUT ON A PROTECTIVE SPLASH GOGGLE AND GLOVE WHEN YOU USE THE SOLVENT. KEEP THE SOLVENT AWAY FROM SPARKS, FLAME, AND HEAT. THE SOLVENT IS A POISONOUS AND FLAMMABLE MATERIAL WHICH CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
(1)  
If the drain line has blockage, remove the blockage with the compressed air.

(2)  
If the drain line has carbon material, clean the drain line with the solvent:
　
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