TM-9-2320-361-24-1 Field Maintenance Manual Volume 1 for M44A2 Series Trucks
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TM 9-2320-361-24-1 0010 00 0010 00-6 COMPRESSED AIR AND BRAKE SYSTEM TROUBLESHOOTING (Contd) Table 2. Service Brakes Troubleshooting Procedures (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 2. EXCESSIVE PEDAL PRESSURE REQUIRED TO STOP VEHICLE (BRAKE PEDAL STOPS TWO INCHES OR MORE ABOVE FLOORBOARD); NO APPARENT AIR SYSTEM FAILURE 1. Check service brakeshoe (1) linings for oil or grease contamination. 2. Direct assistant to apply service brakes and listen for evidence of air escaping at air hydraulic cylinder (2) and at vent (5). Test 1. Check air-hydraulic cylinder (2) for proper delivery line (7) supply pressure. 1. Stop engine and open all drain valves (TM 9-2320-361-10) until brake system air pressure is completely drained. 2. Remove two screws (3) and shield (4) from air-hydraulic cylinder (2). 3. Disconnect delivery line (7) from elbow (6). 4. Remove elbow (6) from air- hydraulic cylinder (2). 5. Install tee (9) on air-hydraulic cylinder (2). 6. Connect test gauge (8) and delivery line (7) to tee (9). 7. Direct assistant to start engine (TM 9-2320-361-10) and allow air pressure to build to normal operating pressure. NOTE Air pressure gauge in instrument panel has a maximum pressure reading of 120 psi. If old governor has been replaced with new governor, air pressure may exceed maximum pressure reading on instrument panel gauge. 8. Check test gauge (8) reading and compare with reading on instrument panel air pressure gauge. If service brakeshoe (1) linings are saturated with oil or grease, repair oil or grease leak and replace brakeshoes (WP 0167 00). 1. If escaping air is present, replace air-hydraulic cylinder (WP 0171 00). 2. If no air is escaping, proceed to test 1. 1. If reading on test gauge (8) is same as instrument panel air pressure gauge, replace air hydraulic cylinder (2) (WP 0171 00). 2. If reading on test gauge (8) is less than instrument panel air pressure gauge, check delivery line (7) for restrictions. If delivery line (7) is damaged or restricted, replace (TM 9-243).