Leak Test of the Vacuum Toilet System

TASK 38-31-00-790-003-A
Leak Test of the Vacuum Toilet System

1. Reason for the Job
To examine the system after the installation of the vacuum generator 37MG.

NOTE: To do this test, a serviceable vacuum generator must be installed.

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

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	1	STOPWATCH
9501501-4000	1	VACUUM TOILET-LEAK TESTER

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TSM 38-31-00-810-854	Vacuum Pressure of the Vacuum System is Too Low
Measuring Tool
Pressure - Altitude Graph

3. Job Set-up
Subtask 38-31-00-860-073-A

A. Preparation for a Leak Test
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001)

Subtask 38-31-00-941-070-A

B. Put an ACCESS PLATFORM 2M (6 FT) in position below the vacuum-system overboard vent.

Subtask 38-31-00-480-060-A

WARNING: ALWAYS WEAR RUBBER GLOVES, GOGGLES AND PROTECTIVE CLOTHES WHEN YOU DO THIS TASK.

C. Installation of the Test Tool 9501501-4000 VACUUM TOILET-LEAK TESTER.

Measuring Tool

(1) Clean the component interfaces and the adjacent area.
(2) Make sure that the Leak Tester is in the correct condition and the date of the calibration is not expired.
(3) Put the indication unit (P/N 9501501-4100) and the test plug (P/N 9501501-4400) in position in the overboard vent.
(4) Make sure that the mark on the test plug is at the forward edge of the fuselage.
(5) Make sure that you can clearly read the manometer.
(6) Tighten the serrated nut of the test plug with your hand to lock the tool in the overboard vent.
(7) Close the manual ventilation valve of the measuring tool.

4. Procedure
Subtask 38-31-00-790-064-A

A. Leak Test of the Vacuum Toilet System
(1) Do this test after the installation of the vacuum generator 37MG and record the results.
(2) Make sure that the measured differential pressure values (result) are not below the limits given in the Figure.

Pressure - Altitude Graph

NOTE: All values shown in this test are negative pressure.

Leak Test

ACTION	RESULT
1.In a lavatory:	At the manometer:
Push and release the toilet flush switch.
Use a STOPWATCH and record the time of the flush cycle.	After 30 seconds record the value and compare it with the calculated value from graph 1. After 120 seconds record the value and compare it with the calculated value from graph 2.
At the measuring tool: Open the manual ventilation valve and release the pressure. After 2 minutes close the manual ventilation valve.	At the manometer: The pressure is zero.
2.In a lavatory:	At the manometer:
Push and release the toilet flush switch.
Use a STOPWATCH and record the time of the flush cycle.	After 30 seconds record the value and compare it with the calculated value from graph 1. After 120 seconds record the value and compare it with the calculated value from graph 2.
At the measuring tool: Open the manual ventilation valve and release the pressure. After 2 minutes close the manual ventilation valve.	At the manometer: The pressure is zero.
3.In the lavatory:	At the manometer:
Push and release the toilet flush switch.
Use a STOPWATCH and record the time of the flush cycle.	After 30 seconds record the value and compare it with the calculated value from graph 1. After 120 seconds record the value and compare it with the calculated value from graph 2.
At the measuring tool: Open the manual ventilation valve and release the pressure.

(3) If the result of the leak test is not satisfactory, refer to the trouble shooting procedure TSM 38-31-00-810-854.

5. Close-up
Subtask 38-31-00-080-059-A

A. Removal of the Test Tool

WARNING: ALWAYS WEAR RUBBER GLOVES, GOGGLES AND PROTECTIVE CLOTHES WHEN YOU DO THIS TASK.

(1) Disconnect the indication unit and the test plug from the overboard vent.
(2) Clean the component interfaces and the adjacent area.

Subtask 38-31-00-942-072-A

B. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the access platform(s).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(4) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.04.01 01:19:49 UTC