Operational Test of the APU Fuel-Pump System on Ground to Purge the Fuel Line

TASK 28-22-00-710-001-A
Operational Test of the APU Fuel-Pump System on Ground to Purge the Fuel Line

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 3M (10 FT)
No specific	AR	CONTAINER 5 L (1.32 USGAL)
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 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 52-41-00-010-001-A	Open the APU Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access

3. Job Set-up
Subtask 28-22-00-860-052-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the APU section of the overhead panel 25VU, make sure that the APU MASTER SW is in the off position (the ON legend is off).
(3) On the FUEL overhead panel 40VU, make sure that all L TK PUMPS and R TK PUMPS pushbutton switches are released (the OFF legends are on).

Subtask 28-22-00-865-050-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

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/LP VALVE/CTL	1QF	M40
121VU	APU/FUEL/LP VALVE/SPLY	2QF	M39
121VU	APU/FUEL/PUMP/CTL	3QC	M38
** ON A/C NOT FOR ALL
121VU	APU/FUEL/BLOW OFF/CTL	1QC	P38

Subtask 28-22-00-010-050-A

C. Get Access

WARNING: LOCK THE MECHANISM OF THE ACCESS DOOR 316AR WITH THE PIP PIN WHEN YOU OPEN THE ACCESS DOOR. THIS WILL PREVENT INJURY.

(1) Put the ACCESS PLATFORM 3M (10 FT) in position below the APU compartment.
(2) Open the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Remove the blanking plug from the APU fuel vent and drain valve and install the 98A28007570000 ADAPTER - VENT AND DRAIN VALVE, APU.
(4) Put a CONTAINER 5 L (1.32 USGAL) below the APU fuel vent and drain valve to collect the fuel.
(5) Make sure that the outlet from the drain mast at FR47 has no blockage.

4. Procedure
Subtask 28-22-00-710-050-A

A. Do this test.

ACTION	RESULT
1.On the front firewall FR80 in the APU compartment: push and hold the pushbutton switch VENT APU FUEL LINE 8QC.	At the APU fuel vent and drain valve: a continues flow of fuel shows that the APU fuel pump 4QC operates.
2.On the front firewall FR80 in the APU compartment: release the pushbutton switch VENT APU FUEL LINE 8QC.	At the APU fuel vent and drain valve: the flow of fuel stops when the APU fuel pump 4QC does not operate.

5. Close-up
Subtask 28-22-00-860-053-A

A. Put the aircraft back to its initial configuration.
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(2) Put the system back to the serviceable condition.

Subtask 28-22-00-410-050-A

B. Close Access
(1) Remove the 98A28007570000 ADAPTER - VENT AND DRAIN VALVE, APU and replace the blanking plug and tighten.
(2) Make sure that the work area is clean and clear of tools and other items.
(3) Close the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.01 04:21:35 UTC