Table 3-1. Operator Troubleshooting Table (Cont)
TEST OR INSPECTION
BRAKES WILL NOT RELEASE.
Step 1. Check that tractor to semitrailer air supply is turned on.
If air is shut off, turn on air supply.
If air supply is on, proceed to step 2.
Step 2. Check air pressure of truck tractor.
If pressure is low, build up air pressure to normal level.
If pressure is normal, proceed to step 3.
Step 3. Check connections of air lines to air hose couplings.
If air lines are not properly connected (Emergency to Emergency, Service to Service),
connect air lines.
If air lines are connected properly, proceed to step 4.
Step 4. Check for dirty or leaking air hose couplings.
If coupling is leaking, notify organizational maintenance.
If coupling is clean and not leaking, proceed to step 5.
Step 5. Inspect brake hoses and connectors for leaks.
If hoses or connectors are leaking, notify organizational maintenance.
If hoses or connectors are good, proceed to step 6.
Step 6. Check semitrailer air reservoirs for open drain cock.
If drain cock is open, close it.
If drain cock is closed, notify organizational maintenance.
Check for moisture in air reservoir by opening drain cock (para. 3-8).
If moisture is in reservoir, allow to drain.
If reservoir is dry and malfunction is not corrected, notify organizational maintenance.