Leak Test of ACT Vent/Transfer Pipe-Shrouds and Cavity Drain Lines

TASK 28-28-00-790-005-A
Leak Test of ACT Vent/Transfer Pipe-Shrouds and Cavity Drain Lines

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

1. Reason for the Job
To make sure that the ACT pipe-shrouds and cavity drain lines are in good condition before the installation of the ACT.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	2	ADAPTER - EXTENSION, FILLING SYSTEM, DRY AIR
No specific	AR	AIR SOURCE 2 BAR (30 PSI) - REGULATED, FILTERED, DRY
No specific	2	CAP - BLANKING
No specific	AR	GAGE 5 BAR (75 PSI) - PRESSURE
No specific	AR	PLUG - BLANKING
No specific	1	WARNING NOTICE(S)
No specific	Torque wrench: range to between 3.33 and 3.0 m.daN (24.56 and 22.12 lbf.ft )
98D28108563000	4	COVER, FUEL VENT-ACT

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
134AR, 154AR, 195BB, 197AB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-11-27-000-001-A	Removal of the Additional Center Tank (ACT)
TASK 28-28-53-000-001-A	Removal of the ACT Transfer-Valve Actuator
TASK 28-28-53-400-001-A	Installation of the ACT Transfer-Valve Actuator
TASK 28-28-71-000-001-A	Removal of the ACT Isolation-Valve Actuator
TASK 28-28-71-400-001-A	Installation of the ACT Isolation-Valve Actuator
TASK 28-28-72-000-001-A	Removal of the ACT Vent-Valve Actuator
TASK 28-28-72-400-001-A	Installation of the ACT Vent-Valve Actuator
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
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
ACT Cavity Drain Connection ** ON A/C NOT FOR ALL
ACT Transfer Valve ** ON A/C NOT FOR ALL
Access to the ACT Cavity Drain-Line (Aft ACT)
Test Arrangement ACT
ACT Cavity Drain-Connection ** ON A/C NOT FOR ALL
ACT Transfer Valve ** ON A/C NOT FOR ALL
ACT Vent-Valve-Actuator Position-Indicator 91QH ** ON A/C NOT FOR ALL
Access to the ACT Cavity Drain-Line (Forward ACT) ** ON A/C NOT FOR ALL
Test Arrangement ACT ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-28-00-860-186-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Open refuel/defuel panel 800VU and 801VU and make sure that:

The "MODE SELECT" switch is in "OFF" position,
All "REFUEL VALVE" switches are in the "NORM" position.

(a) Close refuel/defuel panel 800VU 801VU.

(3) Make sure that a WARNING NOTICE(S) is(are) in position on these panels to tell persons not to operate the refuel/defuel system:

Refuel/defuel panel 800VU 801VU
Fuel panel 40VU
Fuel panel 28VU.

Subtask 28-28-00-010-096-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the main gear doors (Ref. AMM TASK 32-12-00-010-001) to get access:

to the ACT Transfer-Valve Actuator (6QH)
to the ACT cavity drain-line in the Main Landing Gear (MLG) bay.

(a) Put an ACCESS PLATFORM 1M(3 FT) on the left site of the MLG bay.
(2) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(3) Make sure that the Additional Center Tanks (ACT)s are removed from the aft cargo-compartment (Ref. AMM TASK 28-11-27-000-001).

Subtask 28-28-00-010-096-C ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the main gear doors (Ref. AMM TASK 32-12-00-010-001) to get access:

To the ACT transfer-valve actuator (6QH)
To the ACT forward-isolation-valve actuator (92QH)
To the ACT cavity drain-line in the Main-Landing Gear (MLG) bay.

(a) Put an ACCESS PLATFORM 1M(3 FT) on the left side of the MLG bay.
(2) Open access door 195BB to get access to the ACT vent-valve actuator (91QH).
(3) Open the forward and aft cargo-compartment doors (Ref. AMM TASK 52-30-00-860-001).
(4) For the ACT(s) installed on the lower fuselage, get access to the ACT cavity drain-lines below the applicable ACT(s).

NOTE: Removal of the access panel(s) is only necessary if the applicable ACT(s) is(are) installed and to be tested.

(a) Remove the access panels from the lower fuselage:

For ACT AFT1, remove panel 197AB.
For ACT AFT2, remove panel 154AR.
For ACT FWD, remove panel 134AR.

4. Procedure
Subtask 28-28-00-480-052-A ** ON A/C NOT FOR ALL

A. Installation of the Test Tool
(1) Check the openings of the ACT cavity drain-line system:

ACT Cavity Drain Connection ** ON A/C NOT FOR ALL

(a) Make sure that the PLUG - BLANKING (4) is removed from the line-end of the hose connection (3) of ACT1.

NOTE: This line-end connection must stay open at begin of the first starting flow test.

(b) Make sure that remaining line-end connections of the ACT cavity drain-line system are closed with PLUG - BLANKING.
(2) In the aft cargo-compartment, make sure that the 98D28108563000 COVER, FUEL VENT-ACT is installed on the ACT Vent/Transfer Pipe Shroud connections.
(3) Open the ACT transfer-valve:
(a) Remove the ACT transfer-valve actuator (6QH) (Ref. AMM TASK 28-28-53-000-001).

NOTE: It is sufficient, to remove temporary only the actuator, so that you can open the valve manually.
The given removal of the valve mounting flange is not necessary.

(b) Open the ACT Transfer-Valve (165QM) manually with a screwdriver.

ACT Transfer Valve ** ON A/C NOT FOR ALL

(4) On the right site of the MLG bay, install the Test Tool on the ACT cavity drain-line:

Access to the ACT Cavity Drain-Line (Aft ACT) ** ON A/C NOT FOR ALL

Test Arrangement ACT ** ON A/C NOT FOR ALL

(a) Loosen the nut (5) and disconnect the elbow (7) from the T-connection.
(b) Put a CAP - BLANKING on the T-connection.
(c) Loosen the nut (6) of the aft cavity drain-line and remove the elbow (7).
(d) Connect an AIR SOURCE 2 BAR (30 PSI) - REGULATED, FILTERED, DRY and a GAGE 5 BAR (75 PSI) - PRESSURE with the applicable ADAPTER - EXTENSION, FILLING SYSTEM, DRY AIR to the cavity drain-line.

Subtask 28-28-00-790-056-A ** ON A/C NOT FOR ALL

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

B. Flow Test on the ACT cavity drain-line.

ACTION	RESULT
In the MLG bay, at the ACT cavity drain-line connection: Start the Ground Pressure Generator (GPG). Set the GPG pressure to 0.7 bar (10 psi). Start to pressurize the ACT cavity drain-line.	On the GPG pressure gage: The air pressure increases up to 0.7 bar (10 psi). On the GPG output pressure gage: Make sure that the air pressure is 0 bar (0 psi).
At the open line end of the ACT drain-line hose (3): Check the line end with your finger.	At the open line end: Make sure that air flows constantly out of the open line end, Make sure that there is no blockage in the ACT cavity drain-line.
If no air comes out of the line end, or if the air-flow is too weak: Stop the flow test, Check all connected pipes and tubes of the ACT cavity drain-line, Remove the possible blockage, Do this flow test again.
In the MLG bay, at the ACT cavity drain-line connection: Stop the Ground Pressure Generator (GPG).	On the GPG pressure gage: The air pressure decreases down to 0 bar (0 psi).

(1) After the flow test:
(a) Install a PLUG - BLANKING (4) on the open line end of the ACT1 drain-line hose (3).
(b) Make sure that all line ends of the cavity drain-line system are closed with PLUG - BLANKING before you continue with the next follow leak test.

Subtask 28-28-00-790-055-A ** ON A/C NOT FOR ALL

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

C. Leak Test of the ACT Vent/Transfer Pipe Shroud

ACTION	RESULT
1.In the MLG bay, on the ACT cavity drain-line: Start the ground pressure generator Carefully pressurize the ACT cavity drain-line to 1.4 bar (20.3053 psi).	On the ground-pressure-generator pressure gage: The air pressure in the ACT cavity drain-line increases to 1.4 bar (20.3053 psi).
2.Close the ground-pressure-generator shutoff valve.	On the ground-pressure-generator pressure gage: Make sure that the air pressure in the ACT cavity drain-line is stable at 1.4 bar (20.3053 psi) for 15 minutes.
3.If the pressure at the ACT cavity drain-line does not stay constant for 15 minutes, find leak(s): Do a leak check of the ACT-cavity drain-line connections and the ACT-vent/transfer pipe-shroud connections Use a soap solution or a leak detector spray to find leak(s).	On the ACT vent/transfer pipe-shrouds and the ACT cavity drain-line: Make sure that there are no leaks. NOTE: Leaks are not permitted. If you find leak(s), do an approved repair and do this test again.
4.In the MLG bay, on the ACT cavity drain-line: Stop the ground pressure generator Carefully release the air pressure from the ACT cavity drain-line.	On the ground-pressure-generator pressure gage: The air pressure in the ACT cavity drain-line decreases to 0 bar (0.0000 psi).

Subtask 28-28-00-080-052-A ** ON A/C NOT FOR ALL

D. Removal of the Test Tool
(1) On the right site of the MLG bay, remove the Test Tool from the ACT cavity drain-line:
(a) Disconnect the Test Tool from the ACT cavity drain-line.
(b) Remove the PLUG-BLANKING from each disconnected line end.
(c) Clean the component interfaces and the adjacent area.
(d) Do an inspection of the component interfaces and the adjacent area.
(2) Assemble the ACT cavity drain-line:
(a) Connect the elbow (7) to the ACT cavity drain-line and tighten the nut (6).
(b) Connect the elbow (7) to the T-connection and tighten the nut (5).
(3) Close the ACT Transfer-Valve:
(a) Close the ACT Transfer-Valve (165QM) manually with a screwdriver.
(b) Install the ACT Transfer-Valve Actuator (6QH) (Ref. AMM TASK 28-28-53-400-001).

Subtask 28-28-00-480-052-E ** ON A/C NOT FOR ALL

E. Installation of the Test Tool
(1) Check the openings on the forward and aft section of ACT cavity-drain line system:
(a) On the lower fuselage, get access to the applicable cavity drain lines on the installed ACT(s):

ACT Cavity Drain-Connection ** ON A/C NOT FOR ALL

1 Disconnect the hose (3) from the drain fitting (1).
2 Put a CAP - BLANKING on the drain fitting (1) on the ACT.
(b) On the aft section:

Make sure that the PLUG - BLANKING (4) is removed from the line end of the hose connection (3) of ACT AFT1.

Make sure that the PLUG - BLANKING (4) is removed from the line end of the hose connection (3) of ACT FWD.

NOTE: These line end connections must stay open at starting of flow test.

(d) Make sure that remaining line end connections of ACT AFT2 and ACT AFT3 are closed with PLUG - BLANKING.
(2) If ACTs have been removed in the forward or aft cargo compartment, make sure that:

The 98D28108563000 COVER, FUEL VENT-ACT is installed on the ACT vent/transfer pipe-shroud-connections.

(3) Open the ACT transfer valve:
(a) Remove the ACT transfer-valve actuator (6QH) (Ref. AMM TASK 28-28-53-000-001).

NOTE: It is necessary to remove the actuator, so that you can open the valve manually.
The given procedure for removal of the valve mounting flange is not necessary.

(b) Open the ACT transfer valve (165QM) manually with a screwdriver.

ACT Transfer Valve ** ON A/C NOT FOR ALL

(4) Make sure that the indication for the ACT forward-isolation-valve actuator (92QH) shows the open position.
(a) If the ACT forward-isolation valve (236QM) is closed, remove the ACT forward isolation-valve-actuator (92QH) (Ref. AMM TASK 28-28-71-000-001) and open the valve manually.
(5) In the blue hydraulic compartment, make sure that the indication for the ACT vent-valve actuator (91QH) shows the open position.

ACT Vent-Valve-Actuator Position-Indicator 91QH ** ON A/C NOT FOR ALL

(a) If the ACT vent valve (234QM) is closed, remove the ACT vent-valve actuator (91QH) (Ref. AMM TASK 28-28-72-000-001) and open the valve manually.
(6) On the right side of the MLG bay, install the test tools on the forward and aft ACT cavity-drain line:

Access to the ACT Cavity Drain-Line (Forward ACT) ** ON A/C NOT FOR ALL

Access to the ACT Cavity Drain-Line (Aft ACT) ** ON A/C NOT FOR ALL

Test Arrangement ACT ** ON A/C NOT FOR ALL

NOTE: If there is only one test tool available, do the leak test of the ACT vent/transfer pipe-shroud to the aft cargo compartment first.

(a) Disconnect the ACT cavity-drain line from the T-connection.
(b) Put a CAP - BLANKING on the T-connection.
(c) Loosen the nut (6) of the ACT cavity-drain line and remove the elbow (7).
(d) Connect an AIR SOURCE 2 BAR (30 PSI) - REGULATED, FILTERED, DRY and a GAGE 5 BAR (75 PSI) - PRESSURE with the applicable ADAPTER - EXTENSION, FILLING SYSTEM, DRY AIR on the forward and aft cavity-drain line.

Subtask 28-28-00-790-056-E ** ON A/C NOT FOR ALL

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

F. Flow Test on the ACT cavity-drain line.

NOTE: This flow test is divided in two separate test work steps.

ACTION	RESULT
Flow Test on the aft section of the ACT cavity-drain line.
In the MLG bay, at the aft drain line connection: Start the Ground Pressure Generator (GPG). Set the GPG pressure to 0.7 bar (10 psi). Start to pressurize the aft ACT cavity-drain line.	On the GPG pressure gage: The air pressure increases up to 0.7 bar (10 psi). On The GPG output pressure gage: Make sure that the air pressure is 0 bar (0 psi).
At the open line end of the drain line hose (3) of ACT AFT1: Check the line end with your finger.	At the open line end: Make sure that air flows constantly out of the open line end. Make sure that there is no blockage in the aft ACT cavity-drain line.
If no air comes out of the line end, or if the airflow is too weak: Stop the flow test. Check all connected pipes and tubes of the aft ACT cavity-drain line. Remove the possible blockage. Do this flow test again.
In the MLG bay, at the aft drain-line connection: Stop the Ground Pressure Generator (GPG).	On The GPG pressure gage: The air pressure decreases down to 0 bar (0 psi).
Flow test on the forward section of the ACT cavity-drain line.
In the MLG bay, at the forward drain-line connection: Start the GPG. Set the GPG pressure to 0.7 bar (10 psi). Start to pressurize the forward section of the ACT cavity-drain line.	On the GPG pressure gage: The air pressure increases up to 0.7 bar (10 psi). On the GPG output pressure gage: Make sure that the air pressure is 0 bar (0 psi).
At the open line end of the drain line hose of ACT FWD: Check the line end with your finger.	At the open line end: Make sure that air flows constantly out of the open line end. Make sure that there is no blockage in the forward ACT cavity-drain line.
If no air comes out of the line end, or if the airflow is too weak: Stop the flow test. Check all connected pipes and tubes of the forward ACT cavity-drain line. Remove the possible blockage. Do this flow test again.
In the MLG bay, at the forward drain-line connection: Stop the GPG.	On the GPG pressure gage: The air pressure decreases down to 0 bar (0 psi).

(1) After the flow test:
(a) On the aft section of the ACT cavity-drain line, install a PLUG - BLANKING on line end of the hose of ACT AFT1.
(b) On the forward section of the ACT cavity-drain line, install a PLUG - BLANKING line end of the hose of ACT FWD.
(c) Make sure that all line ends of the ACT cavity-drain line system are close with PLUG - BLANKING before you continue with the next follow leak test.

Subtask 28-28-00-790-055-B ** ON A/C NOT FOR ALL

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

G. Leak Test of the ACT Vent/Transfer Pipe Shroud

NOTE: This procedure shows the leak test of the forward and aft ACT-vent/transfer pipe-shroud connections at the same time.

ACTION	RESULT
1.In the MLG bay, on the forward and aft ACT cavity drain-line: Start the ground pressure generator Carefully pressurize the ACT cavity drain-line to 1.4 bar (20.3053 psi).	On the ground-pressure-generator pressure gage: The air pressure in the ACT cavity drain-line increases to 1.4 bar (20.3053 psi).
2.Close the ground-pressure-generator shutoff valve.	On the ground-pressure-generator pressure gage: Make sure that the air pressure in the ACT cavity-drain line is stable at 1.4 bar (20.3053 psi) for 15 minutes.
3.If the pressure at the ACT cavity drain-line does not stay constant for 15 minutes, find leak(s): Do a leak check of the ACT-cavity drain-line connections and the ACT-vent/transfer pipe-shroud connections Use a soap solution or a leak detector spray to find leak(s).	On the ACT vent/transfer pipe-shrouds and the ACT cavity drain-line: Make sure that there are no leaks. NOTE: Leaks are not permitted. If you find leak(s), do an approved repair and do this test again.
4.In the MLG bay, on the ACT cavity-drain line: Stop the ground pressure generator Carefully release the air pressure from the ACT cavity drain-line.	On the ground-pressure-generator pressure gage: The air pressure in the ACT cavity drain-line decreases to 0 bar (0.0000 psi).

Subtask 28-28-00-080-052-E ** ON A/C NOT FOR ALL

H. Removal of the Test Tool
(1) On the right side of the MLG bay, disconnect the test tools from the ACT cavity-drain line:
(a) Remove the PLUG-BLANKING from each disconnected line end.
(b) Clean the component interfaces and the adjacent area.
(c) Do an inspection of the component interfaces and the adjacent area.
(d) Assemble the forward and aft ACT-cavity-drain line.
(2) Close the ACT transfer valve:
(a) Close the ACT transfer valve (165QM) manually with a screwdriver.
(b) Install the ACT transfer-valve actuator (6QH) (Ref. AMM TASK 28-28-53-400-001).
(3) If removed for the test, install the ACT forward-isolation-valve actuator (92QH) (Ref. AMM TASK 28-28-71-400-001).
(4) If removed for the test, install the ACT vent-valve actuator (91QH) (Ref. AMM TASK 28-28-72-400-001).
(5) On the lower fuselage, at the ACT cavity drains of the installed ACT(s):

ACT Cavity Drain-Connection ** ON A/C NOT FOR ALL

(a) Remove the PLUG-BLANKING from each disconnected line end.
(b) Remove the cap blanking from the drain fitting of the ACT.
(c) Clean the component interfaces and the adjacent area.
(d) Do an inspection of the component interfaces and the adjacent area.
(e) Connect the ACT cavity-drain lines to the ACT(s).
(f) Install the hose (3) on the drain fitting (1) with the nut (2).

CAUTION: MAKE SURE THAT THE FLEXIBLE HOSES ARE NOT TWISTED OR PULLED TIGHT. IF THE HOSES ARE TWISTED OR PULLED TIGHT, THE CONNECTIONS WILL BREAK AND CAUSE A LEAK.

(g) TORQUE the nut (2) to between 3.33 and 3.0 m.daN (24.56 and 22.12 lbf.ft )

5. Close-up
Subtask 28-28-00-410-076-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Remove the access platform(s).
(2) Close the main gear doors (Ref. AMM TASK 32-12-00-410-001).
(3) Close the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).

Subtask 28-28-00-410-076-C ** ON A/C NOT FOR ALL

A. Close Access
(1) Remove the access platform(s).
(2) Close access door 195BB.
(3) Close the main gear doors (Ref. AMM TASK 32-12-00-410-001).
(4) Close the forward and aft cargo-compartment doors (Ref. AMM TASK 52-30-00-860-002).
(5) On the lower fuselage, install the applicable access panels of the ACT cavity-drain:

For ACT AFT1, install panel 197AB.
For ACT AFT2, install panel 154AR.
For ACT FWD, install panel 134AR.

Subtask 28-28-00-860-187-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.
(1) Remove the WARNING NOTICE(S).
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(3) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.04.01 00:08:49 UTC