Removal of the Valve Blocks of the Power Control Unit (Flap)

TASK 27-54-53-000-001-A
Removal of the Valve Blocks of the Power Control Unit (Flap)

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

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.

NOTE: The removal procedure for the valve block 23CV is specified. The removal procedure for the valve block 24CV is almost the same. If there are differences in the procedures they are specified.

FIN: 23CV
FIN: 24CV

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 3M (10 FT)
No specific	AR	CAP - BLANKING
No specific	1	CONTAINER 5 L (1.32 USGAL)
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)
98D27803000000	1	LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION

B. Referenced Information

REFERENCE	DESIGNATION
TASK 27-00-00-480-002-A	Installation of the Flap/Slat Control-Lever Locking Tool (98D27803000000)
TASK 27-50-00-480-802-A	Installation/Removal of the Check Pin at Track 1
TASK 27-50-00-866-009-A	Retraction of the Flaps on the Ground
TASK 27-50-00-866-009-A-01	Retraction of the Flaps/Slats on the Ground
TASK 27-54-00-820-001-A	Adjustment of the Flap Drive System
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
Valve Block

3. Job Set-up
Subtask 27-54-53-866-050-A

A. Retraction of the Flaps
(1) Retract the flaps to the 0 degree position (Ref. AMM TASK 27-50-00-866-009).
(2) Install the 98D27803000000 LOCKING TOOL-FLAP SLAT LEVER,INT. POSITION (Ref. AMM TASK 27-00-00-480-002) on the slat/flap control lever.

Subtask 27-54-53-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1	6CV	B07
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/FLP/CTL AND MONG/SYS1	6CV	B02
** ON A/C ALL
121VU	FLIGHT CONTROLS/FLP/CTL AND/MONG/SYS2	8CV	Q21

Subtask 27-54-53-010-050-A

C. Open the main doors of the main gear (Ref. AMM TASK 32-12-00-010-001).

Subtask 27-54-53-860-050-B

D. Aircraft Maintenance Configuration
(1) Put the ACCESS PLATFORM 3M (10 FT) in position at the main gear main door opening.
(2) Make sure that the Green and Yellow hydraulic systems are depressurized and put them in the maintenance configuration (Ref. AMM TASK 29-00-00-864-001).
(3) Depressurize the reservoirs of the Green and Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-001).
(4) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the hydraulic systems.
(5) Put a CONTAINER 5 L (1.32 USGAL) in position below the Power Control Unit (PCU) (1).
(6) Install the check pins at the left and right flap tracks 1 (Ref. AMM TASK 27-50-00-480-802).
(a) If you cannot install the check pins easily, do the adjustment of the L/H (R/H) flap drive system (Ref. AMM TASK 27-54-00-820-001).

4. Procedure
Subtask 27-54-53-020-050-A

A. Removal of the Valve Block

Valve Block

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.

CAUTION: DO NOT USE POINTED, SHARP OR METAL TOOLS TO REMOVE AND INSTALL PACKINGS OR RETAINERS. ALSO MAKE SURE THAT YOU USE THE CORRECT TOOLS TO REMOVE AND INSTALL LOCKING WASHERS OR RETAINING RINGS. IF YOU DO NOT USE THE CORRECT TOOLS, YOU CAN EASILY CAUSE DAMAGE TO THESE COMPONENTS.

CAUTION: YOU MUST BE CAREFUL WHEN YOU MOVE THE TRANSFER TUBES AND THE ADJACENT COMPONENTS. IF YOU ARE NOT CAREFUL, YOU CAN EASILY CAUSE DAMAGE TO THEM.

(1) To remove the valve block assembly (23), you must remove it together with the Pressure-Off Brake (POB) (41) and the hydraulic motor (7) from the differential gearbox (40):
(a) Disconnect the hydraulic lines (11).
(b) Remove the tie wrap (9) and disconnect the seal drain line (10).
(c) Disconnect the case drain line (8).
(d) Install the blanking caps on the open line ends (8),(10),(11).
(e) Install the PLUG - BLANKING in the ports of the PCU (1).
(f) Disconnect the electrical connector (22) from the valve block assembly (23).
(g) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(h) Remove the bolts (3) and the washers (2).
(i) Support the POB (41), the valve block assembly (23) and the hydraulic motor (7).
(j) Remove the nuts (24) and the washers (25) from the studs (42).
(k) Remove the valve block assembly (23), the POB (41) and the hydraulic motor (7) together from the differential gearbox (40).
(2) Remove the valve block assembly (23) from the POB (41) and the hydraulic motor (7):
(a) Remove the bolts (6) and the washers (5).
(b) Carefully remove the hydraulic motor (7) from the POB (41) and from the transfer tubes (14) on the valve block assembly (23).
(c) Remove and discard the packing (4).
(d) Carefully remove the POB (41) from the transfer tube (33).
(3) Remove and discard the lock washers (21) and retaining ring (30) from the transfer tubes (14) and (33).
(4) Remove the transfer tubes (14) and (33) from the valve block assembly (23).
(5) Carefully remove and discard all the packings (13),(32) and all the retainers (12),(31) from the transfer tubes (14) and (33).

[Rev.10 from 2021] 2026.03.31 23:54:19 UTC