Vacuum Pressure of the Vacuum System is Too Low

TASK 38-31-00-810-854-A
Vacuum Pressure of the Vacuum System is Too Low

1. Possible Causes

toilet drain lines
tank drain line
component of the vacuum toilet system
GENERATOR,VACUUM [37MG]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 38-30-00-010-002	Removal of the Toilet Drain Lines
AMM 38-30-00-410-002	Installation of the Toilet Drain Lines
AMM 38-31-00-790-002	Leak Test of the Vacuum Toilet System
AMM 38-31-64-000-001	Removal of the Vacuum Generator
AMM 38-31-64-400-001	Installation of the Vacuum Generator
AMM 38-31-76-000-001	Removal of the Flush Line Check Valves
AMM 38-31-76-400-001	Installation of the Flush Line Check Valves 3322MM/3323MM

3. Fault Confirmation
Subtask 38-31-00-710-154-A

A. Fault Confirmation Test
(1) Do the leak check of the Vacuum Toilet System AMM 38-31-00-790-002.

4. Fault Isolation
Subtask 38-31-00-810-156-A

A. If the required negative differential pressure (Ref. to the GRAPH 1 and GRAPH 2 in figure 503 of the AMM TASK 38-31-00-790-002) is lower than the measured value:

examine the toilet drain lines for leaks with the vacuum system under pressure.

(1) If you find leaks, repair or replace the defective toilet drain lines AMM 38-30-00-010-002 and AMM 38-30-00-410-002.
(2) If the fault continues:

examine the tank drain line for leaks, if leaks are found:
repair or replace the tank drain line , AMM 38-31-76-000-001 and AMM 38-31-76-400-001.

(3) If you have replaced a component of the vacuum toilet system :

examine the installed component(s) for the correct installation.
make sure that the component(s) does (do) not leak.

(4) If the fault continues:

replace the GENERATOR,VACUUM [37MG] , AMM 38-31-64-000-001 and AMM 38-31-64-400-001.

Subtask 38-31-00-710-155-A

B. Test
(1) Do the test given in Para. 3.
(2) Make sure that the vacuum toilet system operates correctly.

[Rev.8 from Aug 2018] 2026.04.04 04:34:16 UTC