Parking Brake-One motor of the parking brake control valve is inoperative

TASK 32-45-00-040-001-A
Parking Brake-One motor of the parking brake control valve is inoperative

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.

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

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: MAKE SURE THAT THE CONTROLS AGREE WITH THE POSITION OF THE ITEMS THEY OPERATE BEFORE YOU PRESSURIZE A HYDRAULIC SYSTEM. UNWANTED MOVEMENT OF HYDRAULICALLY OPERATED ITEMS CAN CAUSE SERIOUS INJURY AND/OR DAMAGE.

1. Reason for the Job
MMEL 32-45-01A
PARKING BRAKE CONTROL VALVE ELECTRICAL MOTOR
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT)
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.08 and 0.05 m.daN (7.08 and 4.42 lbf.in )

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 29-24-00-863-001-A	Pressurize the Yellow Hydraulic System with the Electric Pump
TASK 29-24-00-864-001-A	Depressurize the Yellow Hydraulic System
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
Parking Brake Electrical Control Valve - Circuit Breakers ** ON A/C NOT FOR ALL
Parking Brake Electrical Control Valve 102GG ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 32-45-00-860-054-A

A. Aircraft Maintenance Configuration
(1) On the panel 400VU, make sure that the landing gear control lever is in the DOWN position.
(2) On the panel 110VU, make sure that the PARKING BRK control-switch is in the OFF position.
(3) Make sure that the CAPT and F/O brake pedals are released.
(4) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002)

Subtask 32-45-00-010-051-A

B. Get Access
(1) Open the right MLG door (Ref. AMM TASK 32-12-00-010-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) in position in zone 744.

Subtask 32-45-00-941-052-A

C. Safety Precautions
(1) Put the WARNING NOTICE(S) to tell persons not to operate:

the landing gear control lever
the brake pedals.

Subtask 32-45-00-865-052-A

D. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	L/G/Y BRK/PRESS/IND	61GG	C10
** ON A/C NOT FOR ALL
49VU	ABCU &/Y BRK/PRESS IND	61GG	C10
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
** ON A/C ALL
121VU	HYDRAULIC/PARK BRK/CTL/STBY	71GG	N37
121VU	HYDRAULIC/PARK BRK/CTL/NORM	70GG	N36
121VU	HYDRAULIC/SOL VALVES/G/Y/PTU	1801GL	N34
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N31

Subtask 32-45-00-210-052-A ** ON A/C NOT FOR ALL

E. In zone 744, on the parking-brake electrical control-valve 72GG, make sure that the two circuit breakers are closed:

circuit breaker closed, you must see a black tape through the transparent cover (2)
circuit breaker open, you must see a white tape through the transparent cover (2).
Parking Brake Electrical Control Valve - Circuit Breakers ** ON A/C NOT FOR ALL

NOTE: If you cannot see the circuit breakers through the transparent covers (2) because they are in bad condition:

remove the transparent covers (2) with their packings (1)
make sure that the circuit breakers are closed
install the transparent covers (2) with their packings (1).
TORQUE the transparent covers (2) to between 0.08 and 0.05 m.daN (7.08 and 4.42 lbf.in )

4. Procedure
Subtask 32-45-00-710-051-A ** ON A/C NOT FOR ALL

A. Operational test of the electric motors of the parking brake control valve

NOTE: The pressure value supplied to the brakes, when the parking brake is applied, is 145 bar plus or minus 10 bar (2100 PSI plus or minus 145 PSI).

ACTION	RESULT
1.Pressurize the Yellow hydraulic system with the electric pump (Ref. AMM TASK 29-24-00-863-001).	Make sure that the pressure of the accumulator increases on the triple indicator until 206 bar (3000 PSI) (the indicator pointer is in the green range).
2.Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-24-00-864-001).
3.On the panel 121VU:
open the circuit breaker 71GG. NOTE: To find the inoperative electric motor of the parking-brake control-valve, you must do the test in two steps: -with 70GG closed and 71GG open -with 71GG closed and 70GG open
4.On the panel 110VU:
put the PARKING BRK control switch 73GG in the ON position.	The triple indicator 60GG, shows the left and right pressure values. In the brake units, make sure that the pistons supplied by the Yellow hydraulic system are in the operating or extended position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRAKE indicator light is on.
5.On the panel 110VU:
put the PARKING BRK control switch 73GG in the OFF position.	On the triple indicator 60GG, the pressure from the Yellow hydraulic system applied to the brakes is zero. In the brake units, the pistons supplied by the Yellow hydraulic system are in the released position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRK indicator light is off. NOTE: If this test (step 3 to step 5) is not OK, the electric motor (NORM) supplied by the service bus 601PP is inoperative.
6.On the panel 121VU:
close the circuit breaker 71GG and open the circuit breaker 70GG.
7.On the panel 110VU:
put the PARKING BRK control switch 73GG in the ON position.	The triple indicator 60GG shows the left and right pressure values. In the brake units, make sure that the pistons supplied by the Yellow hydraulic system are in the operating or extended position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRAKE indicator light is off.
8.On the panel 110VU:
put the PARKING BRK control switch 73GG in the OFF position.	On the triple indicator 60GG, the pressure from the Yellow hydraulic system applied to the brakes is zero. In the brake units, the pistons supplied by the Yellow hydraulic system are in the released position. On the nose landing gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRK indicator light is off. NOTE: If this test (step 6 to step 8) is not OK, the electric motor (STBY) supplied by the HOT BUS 701PP is inoperative.
9.On the panel 121VU: close the circuit breaker 70GG.

NOTE: Only one inoperative electric motor of the parking-brake control valve is permitted.

NOTE: If the electrical motor (STBY), supplied by the HOT BUS 701PP is inoperative, the parking brake valve will not operate if the aircraft is supplied by batteries only.

NOTE: If the electric motor (STBY), supplied by the HOT BUS 701PP is inoperative, aircraft towing is not allowed if the aircraft is supplied by batteries only.

Subtask 32-45-00-710-051-B ** ON A/C NOT FOR ALL

A. Operational test of the electric motors of the parking brake control valve

Parking Brake Electrical Control Valve 102GG ** ON A/C NOT FOR ALL

NOTE: The pressure value supplied to the brakes, when the parking brake is applied, is 145 bar plus or minus 10 bar (2100 PSI plus or minus 145 PSI).

ACTION	RESULT
1.Pressurize the Yellow hydraulic system with the electric pump (Ref. AMM TASK 29-24-00-863-001).	Make sure that the pressure of the accumulator increases on the triple indicator until 206 bar (3000 PSI) (the indicator pointer is in the green range).
2.Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-24-00-864-001).
3.On the panel 121VU:
open the circuit breaker 71GG. NOTE: To find the inoperative electric motor of the parking-brake control-valve, you must do the test in two steps: -with 70GG closed and 71GG open -with 71GG closed and 70GG open
4.On the panel 110VU:
put the PARKING BRK control switch 73GG in the ON position.	The triple indicator 60GG, shows the left and right pressure values. In the brake units, make sure that the pistons supplied by the Yellow hydraulic system are in the operating or extended position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRAKE indicator light is on.
5.On the panel 110VU:
put the PARKING BRK control switch 73GG in the OFF position.	On the triple indicator 60GG, the pressure from the Yellow hydraulic system applied to the brakes is zero. In the brake units, the pistons supplied by the Yellow hydraulic system are in the released position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRK indicator light is off. NOTE: If this test (step 3 to step 5) is not OK, the electric motor (NORM) supplied by the service bus 601PP is inoperative.
6.On the panel 121VU:
close the circuit breaker 71GG and open the circuit breaker 70GG.
7.On the panel 110VU:
put the PARKING BRK control switch 73GG in the ON position.	The triple indicator 60GG shows the left and right pressure values. In the brake units, make sure that the pistons supplied by the Yellow hydraulic system are in the operating or extended position. On the nose landing-gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRAKE indicator light is off.
8.On the panel 110VU:
put the PARKING BRK control switch 73GG in the OFF position.	On the triple indicator 60GG, the pressure from the Yellow hydraulic system applied to the brakes is zero. In the brake units, the pistons supplied by the Yellow hydraulic system are in the released position. On the nose landing gear leg, on the N/W Steering Deactivation Electric-Box 5GC, the PARKING BRK indicator light is off. NOTE: If this test (step 6 to step 8) is not OK, the electric motor (STBY) supplied by the HOT BUS 701PP is inoperative.
9.On the panel 121VU: close the circuit breaker 70GG.

NOTE: Only one inoperative electric motor of the parking-brake control valve is permitted.

NOTE: If the electric motor (STBY), supplied by the HOT BUS 701PP is inoperative, the parking brake valve will not operate if the aircraft is supplied by batteries only.

NOTE: If the electric motor (STBY), supplied by the HOT BUS 701PP is inoperative, aircraft towing is not allowed if the aircraft is supplied by batteries only.

Subtask 32-45-00-860-055-A

B. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002)

5. Close-up
Subtask 32-45-00-942-052-A

A. Removal of Equipment
(1) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(2) Remove the WARNING NOTICE(S).
(3) Remove the access platform(s).

Subtask 32-45-00-410-051-A

B. Close Access
(1) Close the right MLG door (Ref. AMM TASK 32-12-00-410-001).
(2) Make an entry in the applicable logbook to tell the crew which electrical motor (NORM) or (STBY) is inoperative.

[Rev.10 from 2021] 2026.04.01 00:49:50 UTC