Removal of the Priority Valve of the Yellow Hydraulic System

TASK 29-13-33-000-001-A
Removal of the Priority Valve of the Yellow Hydraulic System

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

FIN: 3064GM

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	CONTAINER 2 L (0.53 USGAL)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	2	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
196BB, 198CB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 20-23-21-911-001-A	Removal/Installation of the Bobbins from their Housings and Installation of O-rings, Square Seals, and Back-up Rings on the Bobbins
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-00-00-910-002-A	Safety Procedures of the Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 29-23-00-860-001-A	Disconnection of the Isolation Coupling of the Power Transfer Unit (PTU)
Priority Valve

3. Job Set-up
Subtask 29-13-33-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
** ON A/C ALL
121VU	HYDRAULIC/LOW/LVL/IND	1832GQ	N32
121VU	HYDRAULIC/HYD/QTY/IND	1831GQ	P35
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N31
** ON A/C ALL
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

Subtask 29-13-33-010-050-A

B. Get Access
(1) Open the access door 198CB.
(2) Open the access panel 196BB.

Subtask 29-13-33-860-050-A

C. Aircraft Maintenance Configuration

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.

(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(2) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the Yellow hydraulic system:-

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Yellow hydraulic system.

(3) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(4) Depressurize the reservoir of the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-001).
(5) Put a CONTAINER 2 L (0.53 USGAL) below the PTU manifold of the Yellow hydraulic system.
(6) Disconnect the isolation coupling of the power transfer unit (PTU) (Ref. AMM TASK 29-23-00-860-001).

4. Procedure
Subtask 29-13-33-020-050-A

A. Removal of the Priority Valve
(1) Hold the priority valve (1) and remove the bolts (2) and the washers (3).
(2) Remove the priority valve (1).
(3) Remove the bobbins (5) (Ref. AMM TASK 20-23-21-911-001).
(4) Install a PLUG - BLANKING in the PTU manifold and in the ports of the priority valve (1).

[Rev.10 from 2021] 2026.04.01 00:20:14 UTC