Removal of the Fuel-Pump Pressure-Switch

TASK 28-21-15-000-003-A
Removal of the Fuel-Pump Pressure-Switch

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

CAUTION: BE CAREFUL WHEN YOU DO MAINTENANCE TASKS ON THE WING TRAILING EDGE:

DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE RACEWAYS.
DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE INSTALLATIONS.
MAKE SURE THAT THE ELECTRICAL CABLES ARE INSTALLED CORRECTLY. INCORRECT INSTALLATION CAN CAUSE DAMAGE.

FIN: 23QA
FIN: 24QA
FIN: 27QA
FIN: 28QA
FIN: 39QA ** ON A/C NOT FOR ALL
FIN: 40QA ** 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	AR	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	1	CONTAINER 1 L (1/4 USGAL)
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
FOR [23QA] (PRESS SW-FUEL PUMP NO 1, L WING TK)
FOR [24QA] (PRESS SW-FUEL PUMP NO 1, R WING TK)
FOR [27QA] (PRESS SW-FUEL PUMP NO 2, L WING TK)
FOR [28QA] (PRESS SW-FUEL PUMP NO 2, R WING TK)
No specific	1	SCRAPER - PLASTIC

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [39QA] (PRESS SW-FUEL PUMP NO 1, CTR TK)
734
FOR [40QA] (PRESS SW-FUEL PUMP NO 2, CTR TK)
744

C. Referenced Information

REFERENCE	DESIGNATION
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
Fuel-Pump Pressure Switch ** ON A/C NOT FOR ALL
Fuel-Pump Pressure Switch ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-21-15-941-050-A

A. Safety Precautions

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

(1) You must obey the fuel safety procedures when you do work on the fuel system (Ref. AMM TASK 28-00-00-910-001).
(2) Put the SAFETY BARRIER(S) in position.

Subtask 28-21-15-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 23QA (PRESS SWFUEL PUMP NO 1, L WING TK)
121VU	FUEL/L WING TK/PUMP1 SPLY	1QA	N23
123VU	L WING TK/PUMP 1/STBY SPLY	11QA	AD12
FOR FIN: 27QA (PRESS SWFUEL PUMP NO 2, L WING TK)
121VU	FUEL/L WING TK/PUMP2 SPLY	7QA	N26
FOR FIN: 24QA (PRESS SWFUEL PUMP NO 1, R WING TK)
121VU	FUEL/R WING TK/PUMP1 SPLY	2QA	Q23
123VU	R WING TK/PUMP 1/STBY SPLY	12QA	AE12
FOR FIN: 28QA (PRESS SWFUEL PUMP NO 2, R WING TK)
121VU	FUEL/R WING TK/PUMP2 SPLY	8QA	Q26
** ON A/C NOT FOR ALL
FOR FIN: 39QA (PRESS SWFUEL PUMP NO 1, CTR TK)
121VU	FUEL/CTR TK/PUMP1 SPLY	29QA	P23
FOR FIN: 40QA (PRESS SWFUEL PUMP NO 2, CTR TK)
121VU	FUEL/CTR TK/PUMP2 SPLY	30QA	P26

Subtask 28-21-15-010-050-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in the applicable MLG bay.

Subtask 28-21-15-010-050-B ** ON A/C NOT FOR ALL

C. Get Access

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE LANDING GEAR DOORS ARE CLEAR.

(1) Open the applicable main gear door:
(Ref. AMM TASK 32-12-00-010-001)
(a) FOR [39QA] (PRESS SW-FUEL PUMP NO 1, CTR TK)
open 734

(b) FOR [40QA] (PRESS SW-FUEL PUMP NO 2, CTR TK)
open 744.
(2) Make sure that the 460005835 SLEEVE - GROUND LOCK is on the applicable MLG door actuator.
(3) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in the applicable MLG bay.

4. Procedure

CAUTION: BE CAREFUL WHEN YOU DO MAINTENANCE TASKS ON THE WING TRAILING EDGE:

DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE RACEWAYS.
DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE INSTALLATIONS.
MAKE SURE THAT THE ELECTRICAL CABLES ARE INSTALLED CORRECTLY. INCORRECT INSTALLATION CAN CAUSE DAMAGE.

Subtask 28-21-15-020-050-A

A. Removal of the Fuel-Pump Pressure-Switch
(1) Disconnect the electrical connector (8).

CAUTION: MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.

(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Put a CONTAINER 1 L (1/4 USGAL) below the pressure switch (7).

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.

(4) Cut, remove and discard the lockwire from the sealing valve (3) and the plug (6).
(5) FOR [23QA] (PRESS SW-FUEL PUMP NO 1, L WING TK), [24QA] (PRESS SW-FUEL PUMP NO 1, R WING TK), [27QA] (PRESS SW-FUEL PUMP NO 2, L WING TK), [28QA] (PRESS SW-FUEL PUMP NO 2, R WING TK)
Use a SCRAPER - PLASTIC to remove the sealant on the plug (6).
(6) Hold the pressure switch (7) and loosen the plug (6).
(7) Remove the pressure switch (7) and the plug (6) together.
(8) Remove the plug (6) from the pressure switch (7).
(9) Remove and discard the O-rings (4) and (5).
(10) Put a CAP - BLANKING on the sealing valve (3) and the pressure switch (7).
(11) If damaged, remove the sealing valve (3) as follows:
(a) Loosen the sealing valve (3).
(b) Remove the sealing valve (3) from the bulkhead adapter (1).
(c) Remove and discard the O-ring (2).

[Rev.10 from 2021] 2026.04.02 06:17:24 UTC