TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 16. Check secondary air system relay valve (3) for proper pressure (only spring and service
brake chambers (1) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (2), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (2).
Step 3. Disconnect delivery line (6) from service brake chambers (1) and remove elbow (5) from
relay valve (3).
Step 4. Connect test gauge to delivery port (4).
Step 6. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, proceed to test 16.
b. If pressure is normal, repair or replace blocked delivery line (6).
c. Stop engine, drain air, remove test gauge, and connect delivery line (6).
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