Short Leak Test of the Vacuum Toilet System (VTS)

TASK 38-31-00-790-802-A
Short Leak Test of the Vacuum Toilet System (VTS)

1. Reason for the Job

NOTE: This task gives the instructions necessary to do a short leak test before and after the maintenance work on the equipment installed in the lavatories and the galleys.

NOTE: It is possible to do this procedure with or without water in the water tank.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)

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 25-45-22-000-001-A	Removal of the Toilet Shroud and the Seat
TASK 25-45-22-000-802-A	Removal of the Toilet Shroud of the Space Flex Lavatory
TASK 25-45-22-400-001-A	Installation of the Toilet Shroud and the Seat
TASK 25-45-22-400-802-A	Installation of the Toilet Shroud of the Space Flex Lavatory

3. Job Set-up
Subtask 38-31-00-861-087-A

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 38-31-00-010-103-A

B. Get Access
(1) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the potable water system.
(2) Remove the toilet shroud (Ref. AMM TASK 25-45-22-000-001) (Ref. AMM TASK 25-45-22-000-802).

Subtask 38-31-00-865-135-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACUUM-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACUUM-GEN	33MG	A08
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-E	34MG	A04
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-D	39MG	A03
** ON A/C ALL
2001VU	VACU TOIL SYS-LAV PWR-A	32MG	A01
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACU-SYS	35MG	A06
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-VACU-GEN	33MG	A08
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-G	34MG	A04
2001VU	VACU TOIL SYS-LAV PWR-F	39MG	A03
2001VU	VACU TOIL SYS-LAV PWR-D	45MG	A02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	45MG	A02
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-L	23MG	A05
** ON A/C NOT FOR ALL
2001VU	VACU TOIL SYS-LAV PWR-M	34MG	A04

4. Procedure
Subtask 38-31-00-790-069-A

A. Leak Check of the Vacuum Toilet System

NOTE: This test is only permitted, if there are no other noises and you can listen to fluids in the lines.

(1) Do this test before and after removal/installation of components of the vacuum toilet system.

NOTE: The test for the forward system is given, the test for the aft system is the same.

NOTE: After the shut off valve of the toilet assembly is closed, you have approximately 8 seconds to do the test.

Leak Test

ACTION	RESULT
1. In a forward lavatory:
Push and release the toilet flush switch.	The vacuum generator operates for approximately 15 seconds.

(2) After the shut off valve is closed:
(a) Visually examine the vacuum lines of the toilet assembly.
(b) Listen for fluids in the lines and make sure that there are no leaks.

NOTE: Leaks are not permitted.

(3) Do the test three times.

5. Close-up
Subtask 38-31-00-410-109-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the toilet shroud (Ref. AMM TASK 25-45-22-400-001) (Ref. AMM TASK 25-45-22-400-802).
(3) Remove the WARNING NOTICE(S).

Subtask 38-31-00-862-085-A

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

[Rev.10 from 2021] 2026.04.01 01:19:50 UTC