Compressed Air and Brake System Troubleshooting

TM 9-2320-386-24-1-1

0014 00

Compressed Air and Brake System Troubleshooting (Contd)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

WARNING

Eyeshields must be worn when working with compressed air system.

Failure to wear eyeshields may result in injury to personnel.

Step 1. Allow air pressure to build to normal operating pressure.

Step 2. Loosen air reservoir drainvalves.

a. If a low volume of air pressure is released, perform step 3.

b. If a high volume of air pressure is released, proceed to test 2.

c. If water is present, perform malfunction 9.

Step 3. Check air compressor outlet line for restrictions.

a. If air compressor outlet line is restricted, repair or replace (WP 0167 00 or TM 9-243).

b. If air compressor outlet line is not restricted, proceed to test 2.

Test 2. Check for air pressure at air horn supply line.

Step 1. Stop engine and open all air reservoir drainvalves and allow brake system air pressure to

vent. Close air reservoir drainvalves.

Step 2. Disconnect air horn supply line from air horn elbow.

Step 3. Connect air horn supply line to test gauge.

Step 4. Direct assistant to start engine (TM 9-2320-386-10) and allow sufficient time for pressure to

build.

Step 5. Compare test gauge reading with gauge reading on instrument panel.

a. If low or no air pressure is indicated on test gauge, check air horn supply line for

restrictions or leaks. Repair or replace damaged compressed air lines (WP 0167 00 or

TM 9-243).

b. If air compressor is continuously unloading, and not allowing air compressor to build air

pressure, adjust air governor (WP 0170 00).

c. If air governor adjustment will not increase pressure and/or compressor outlet line is

warm or cool, replace air compressor (WP 0169 00).

END OF TESTING!

2. AIR PRESSURE DOES NOT BUILD UP TO NORMAL OPERATING PRESSURE (ABOVE 90 PSI (621 kPa)

ACCORDING TO GAUGE

Step 1. Check for leaking compressed air lines and fittings.

If leakage is found, repair or replace compressed air lines or fittings (WP 0167 00 or

TM 9-243).

Step 2. Adjust air governor (WP 0170 00).

Step 3. Perform malfunction 1, test 2.

END OF TESTING!

3. AIR PRESSURE EXCEEDS MAXIMUM (GAUGE READS OVER 120 PSI [827 kPa]) AND SAFETY VALVE

OPENS TO RELEASE PRESSURE

Step 1. Check governor signal line for crimps, bends, or leaks.

a. If governor signal line is crimped, bent, or leaking, repair or replace governor signal line

(WP 0170 00).

b. If no restrictions are apparent, proceed to test 1.

Test 1. Check governor signal line pressure.

Step 1. Stop engine and open all air reservoir drainvalves and allow brake system air pressure to

vent. Close air reservoir drainvalves.

0014 00-2