Removal of the Engine-Pump Pressure Switch

TASK 29-13-17-000-040-A
Removal of the Engine-Pump Pressure Switch

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.

WARNING: DO NOT TOUCH THE HYDRAULIC SYSTEM COMPONENTS FOR A SHORT TIME AFTER THE ENGINE IS SHUTDOWN. THE ENGINE COMPONENTS STAY HOT FOR SOME TIME AND CAN CAUSE INJURY.

CAUTION: DO NOT LET HYDRAULIC FLUID FALL ON THE ENGINE. UNWANTED HYDRAULIC FLUID MUST BE REMOVED IMMEDIATELY WITH A CLEAN LINT FREE CLOTH. THE FLUID CAN CAUSE DAMAGE TO THE SURFACE PROTECTION AND TO SOME PARTS.

FIN: 3074GD ** 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 1M (3 FT)-ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	1	CONTAINER 5 L (1.32 USGAL)
No specific	AR	COVER - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	1	WRENCH - STANDARD

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
447AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 29-10-00-864-002-A	Depressurize the Yellow Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
Engine-Pump Pressure Switch
Engine-Pump Pressure Switch

3. Job Set-up
Subtask 29-13-17-860-052-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002).
(2) Depressurize the Yellow hydraulic reservoir (Ref. AMM TASK 29-14-00-614-001).
(3) Put WARNING NOTICE(S) in position to tell persons not to pressurize the Yellow hydraulic system:

on the ground service panel 198CB.

(4) Put WARNING NOTICE(S) on the access door 195BB to tell persons not to pressurize the Yellow hydraulic reservoir.

Subtask 29-13-17-941-052-A ** ON A/C NOT FOR ALL

B. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:

Put a WARNING NOTICE(S) in position to tell persons not to start the engine.

(2) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(3) In the cockpit, on the HYD section of overhead panel 40VU.

Put a WARNING NOTICE(S) in position to tell persons not to pressurize the Yellow hydraulic system.

(4) On overhead maintenance panel 50VU:

Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.

(5) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
(6) Put a CONTAINER 5 L (1.32 USGAL) below the hydraulic tube connection to the pressure switch to collect the hydraulic fluid.

Subtask 29-13-17-865-050-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	HYDRAULIC/Y HYD/PUMP ENG2/MONG	3700GD	Q37

Subtask 29-13-17-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the left fan-cowl door 447AL (Ref. AMM TASK 71-13-00-010-040).
(2) Put the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position at the engine.

4. Procedure
Subtask 29-13-17-020-052-A ** ON A/C NOT FOR ALL

A. Removal of the Engine-Pump Pressure Switch

Engine-Pump Pressure Switch ** ON A/C NOT FOR ALL

PRE SB RA32071-20

(1) Disconnect the electrical connector 3074GD-A from the pressure switch (2).
(2) Put a CAP - BLANKING on the electrical connector 3074GD-A and on the pressure switch (2).
(3) Remove the nuts (4), washers (5), screws (1) and clamp assembly (6) that attach pressure switch (2) to its bracket.
(4) Hold the hydraulic tube reducer with a WRENCH - STANDARD and remove the pressure switch (2).
(5) Remove and discard the packing (3).
(6) Put a COVER - BLANKING on the hydraulic tube and on the port of the pressure switch (2).

END OF PRE SB RA32071-20

Subtask 29-13-17-020-053-A ** ON A/C NOT FOR ALL

B. Removal of the Engine-Pump Pressure Switch

Engine-Pump Pressure Switch ** ON A/C NOT FOR ALL

POST SB RA32071-20

(1) Disconnect the electrical connector 3074GD-A from the pressure switch (4).
(2) Put a CAP - BLANKING on the electrical connector 3074GD-A and on the pressure switch (4).
(3) Remove the bonding jumper (9) from the ground stud terminal 9951DC.
(4) Remove the nuts (1), washers (2), screws (5) and clamp assembly (3) that attach pressure switch (4) to its bracket.
(5) Hold the hydraulic tube reducer with a WRENCH - STANDARD and remove the pressure switch (4).
(6) Remove and discard the packing (8).
(7) Put a COVER - BLANKING on the hydraulic tube and on the port of the pressure switch (4).

END OF POST SB RA32071-20

[Rev.10 from 2021] 2026.04.01 08:06:05 UTC