Removal of the Air Inlet Check-Valve

TASK 28-28-37-000-003-A
Removal of the Air Inlet Check-Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

ZONE: 150
FIN: 231QM1 ** ON A/C NOT FOR ALL

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 2M (6 FT)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT
826

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-11-27-000-003-A	Removal of the Additional Center Tank No.2 (ACT AFT2)
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Air Inlet Check Valve

3. Job Set-up
Subtask 28-28-37-860-060-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(3) Put the WARNING NOTICE(S) on control panels that follow, to tell persons not to operate the refuel/defuel system:

Refuel/defuel control panels 800VU and 801VU
Fuel control panel 40VU
Additional Center Tank (ACT) fuel control panel 28VU.

Subtask 28-28-37-865-060-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	FUEL/ACT AIR SOV/MAN/SPLY	64QH	J20
121VU	FUEL/ACT AIR SOV/AUTO/SPLY	63QH	J19
121VU	FUEL/ACT XFR VLV/MOT2	66QH	J18
121VU	FUEL/ACT XFR VLV/MOT1	65QH	J17
121VU	FUEL/INLET VLV MOT2 AUTO SP AFT 2	44QH2	K16
121VU	FUEL/INLET VLV MOT2 AUTO SP AFT 1	44QH1	K15
121VU	FUEL/INLET VLV/MOT1/AFT 2	84QH	L29
121VU	FUEL/INLET VLV/MOT1/MAN SPLY/AFT 1	46QH	L28
121VU	FUEL/HI/LVL/SPLY	1QJ	L24
121VU	FUEL/RFL/DFL/SPLY	2QU	L23
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L22
121VU	FUEL/ACT VENT VLV/MAN/SPLY	62QH	L21
121VU	FUEL/ACT VENT VLV/AUTO/SPLY	61QH	L20
121VU	FUEL/INLET VLV MAN CTL SPLY AFT 2	81QH	L16
121VU	FUEL/INLET VLV MAN CTL SPLY AFT 1	45QH	L15
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29

Subtask 28-28-37-010-056-C ** ON A/C NOT FOR ALL

C. Get Access
(1) Open aft cargo-compartment door 826 (Ref. AMM TASK 52-30-00-860-001).
(2) Put an ACCESS PLATFORM 2M (6 FT) in position at aft cargo-compartment door 826.
(3) Set CARGO COMPT LIGHT switch 8LU to the ON position.
(4) Remove the ACT AFT2 from the aft cargo-compartment (Ref. AMM TASK 28-11-27-000-003).

4. Procedure
Subtask 28-28-37-020-053-B ** ON A/C NOT FOR ALL

A. Removal of the Check Valve

Air Inlet Check Valve ** ON A/C NOT FOR ALL

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT EQUIPMENT FROM FLEXIBLE HOSES AND RIGID TUBING. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL CAUSE DAMAGE TO THE HOSES AND TUBES.

(1) Loosen the union nut (8) and disconnect the hose (7) from the check valve (4).
(2) Remove the bolts (6) and (9) and the washers (5) and (10) from the check valve (4).
(3) Remove the check valve (4) from the receptacle (1).
(4) Put the PLUG-BLANKING in each disconnected line end.
(5) Remove and discard the O-rings (2) and (3).

[Rev.10 from 2021] 2026.04.02 06:17:57 UTC