TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
10. AIR PRESSURE DOES NOT BUILD TO NORMAL OPERATING PRESSURE (ABOVE 80 PSI (552 kPa))
ACCORDING TO GAUGES
Test 1. Inspect for leaks.
Listen and locate leakage.
a. If leakage is indicated, repair or replace lines or fittings as necessary.
b. If no leakage is indicated, perform test 2.
Test 2. Adjust air governor (para. 3-207).
Test 3. Check air compressor for proper operation (malfunction 9, tests 2, 3, and 4).
END OF TESTING!
11. AIR PRESSURE BUILDS SLOWLY (TAKES EXCESSIVE AMOUNT OF TIME TO BUILD TO 100 PSI (690 kPa))
Perform malfunction 10.
END OF TESTING!
12. AIR PRESSURE EXCEEDS MAXIMUM (GAUGES SHOW OVER 130 PSI (896 kPa)), SAFETY VALVE OPENS TO
RELEASE PRESSURE
Test 1. Check for air loss through air accessories. Perform malfunction 20.
Test 2. Check governor signal line (1) for leaks, bends, and clogs.
Step 1. If leaking, bent, or clogged, repair or replace governor signal line (1) (TM 9-243).
Step 2. If not leaking, bent, or clogged, proceed to test 3.
Test 3. Check governor signal line (1) pressure.
Step 1. Stop engine and open all drainvalves (5), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (5).
Step 3. Disconnect governor signal line (1) from air governor (2).
Step 4. Connect adapter fitting (4) to air governor (2) and tee (3) to adapter (4).
Step 5. Connect test gauge to tee (3).
Step 6. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 7. Compare test gauge reading with gauge readings on instrument panel.
a. If air pressure readings are the same on test and instrument panel gauges, notify DS
maintenance.
b. If air pressure reading is below 80 psi (552 kPa), replace air governor (2)
c. Stop engine, drain air, remove test gauge, and connect signal line (1).
2-200
