Removal of the APU Fuel LP-Switch

TASK 28-22-14-000-001-A
Removal of the APU Fuel LP-Switch

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	AR	CONTAINER 5 L (1.32 USGAL)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)
98A28007570000	1	ADAPTER - VENT AND DRAIN VALVE, APU

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 52-41-00-010-001-A	Open the APU Doors for Access
APU Fuel LP-Switch 5030QM ** ON A/C NOT FOR ALL
APU Fuel LP-Switch 5030QM ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-22-14-865-050-A

A. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	APU/FUEL/BLOW OFF/PUMP	2QC	B14
** ON A/C NOT FOR ALL
121VU	APU/FUEL/BLOW OFF/CTL	1QC	K39
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41
121VU	APU/FUEL/PUMP/CTL	3QC	M38
** ON A/C NOT FOR ALL
121VU	APU/FUEL/BLOW OFF/CTL	1QC	P38

Subtask 28-22-14-941-050-B

B. Safety Precautions
(1) When you do maintenance work on the fuel system you must obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) On the FUEL overhead panel 40VU, make sure that the L TK PUMPS and the R TK PUMPS pushbutton switches are released (the OFF legends are on).
(3) On the APU section of the overhead panel 25VU, make sure that the APU MASTER SW is in the off/released position (the ON legend is off).
(4) Put a WARNING NOTICE(S) in position:

on the overhead panel 25VU, to tell persons not to push the APU MASTER SW,
on the FUEL overhead panel 40VU, to tell persons not to operate the fuel system,
on the FIRE panel 20VU, to tell persons not to operate the APU fire extinguishing system.

Subtask 28-22-14-010-050-B

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU compartment.
(2) Open the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Put a CONTAINER 5 L (1.32 USGAL) below the APU fuel LP switch (1) to collect unwanted fuel.
(4) Remove the blanking plug (7) from the APU vent and drain valve (8).
(5) Install the 98A28007570000 ADAPTER - VENT AND DRAIN VALVE, APU (9) to the fuel vent and drain valve (8).
(6) Drain the unwanted fuel into the container.
(7) Remove the 98A28007570000 ADAPTER - VENT AND DRAIN VALVE, APU (9) when the fuel is drained.

4. Procedure
Subtask 28-22-14-020-052-A

A. Removal of the APU Fuel LP-Switch 5030QM
(1) Disconnect the electrical connector (2) from the APU fuel LP switch (1).
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(3) Remove and discard the lockwire from the union (3) to the nut (4).
(4) Loosen the nut (4) and disconnect from the APU vent and drain valve (8).
(5) Removal of the APU fuel LP-switch:

CAUTION: YOU MUST USE TWO WRENCHES AND HOLD THE COMPONENT WHEN YOU REMOVE/INSTALL THE PIPE COUPLINGS AND/OR UNIONS. THIS PREVENTS DAMAGE TO THE COMPONENT.

(a) Loosen the union assy (5) from the union (3).
(b) Remove the APU fuel LP switch (1) from the union (3).
(c) Remove and discard the 0-rings (6).
(d) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.01 12:42:16 UTC