Removal of the Air Inlet Check Valve

TASK 28-28-37-000-001-A
Removal of the Air Inlet Check Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

FIN: 177QM1 ** ON A/C NOT FOR ALL
FIN: 177QM2 ** 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	1	WARNING NOTICE(S)

B. 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 28-11-27-000-001-A	Removal of the Additional Center Tank (ACT)
TASK 28-11-49-000-001-A	Removal of the ACT Integrated Impact Wall
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 28-28-37-860-057-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 a WARNING NOTICE(S) in position on:

the refuel/defuel panel 801VU,
the fuel panel 40VU,
to tell persons not to operate the refuel/defuel system.

Subtask 28-28-37-010-054-A ** ON A/C NOT FOR ALL

Subtask 28-28-37-010-054-B ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(2) Put an ACCESS PLATFORM 2M (6 FT) in position at the opening of the aft cargo-compartment.
(3) For the Check Valve 177QM2, remove the Integrated Impact Wall from the aft cargo-compartment (Ref. AMM TASK 28-11-49-000-001).
(4) For the Check Valve 177QM1, remove the Additional Center Tank No.2 (ACT2) from the aft cargo-compartment (Ref. AMM TASK 28-11-27-000-001).

Subtask 28-28-37-865-058-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	ACT1/REFUEL & SPLY	33QU	L29
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	FUEL/RFL/DFL/SPLY	2QU	L24
121VU	FUEL/RFL/DFL/XFR/DEFUEL/VALVE	1QU	L23
121VU	ACT XFR VALVE MAN CTL	30QH	N29
121VU	ACT1/CTL & SPLY	9QH	P29
121VU	ACT PUMP SUPPLY	25QH	Q29

4. Procedure
Subtask 28-28-37-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Check Valve
(1) Loosen the union nut (8) and disconnect the pressure line (7) from the check valve (4).
(2) Remove the screws (6) and the washers (5) from the check valve (4).
(3) Remove the check valve (4) from the receptacle (1).
(4) Remove and discard the O-rings (2) and (3).
(5) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.02 06:17:56 UTC