Check vehicle on level ground if possible, set parking brake, block wheels, ensure that all tanks are drained.

Suggested maximum time required for this pre-trip inspection is 30 minutes.

NOTE: Trailer tanks will not require draining for testing purposes only.

CIRCLE CHECK

1. Check security and condition of compressor and belts under hood.
2. Check condition and security of hoses and flex lines and glad hands.
3. Pull all slack adjusters manually (use pry bar if necessary). Check for travel, mechanical condition, wear.

NOTE: A brake adjustment (S cam type only) will be required as part of the Air Brake Examination.

BUILD UP AIR PRESSURE, WATCHING THAT THE:

1. Warning device cuts out at approximately 60 P.S.I.;
2. Pressure builds from 50-90 P.S.I. within five minutes;
3. Governor cuts out between 105 P.S.I. minimum and 125 P.S.I. maximum.
4. Release spring brakes.

Charge trailer and rebuild pressure if necessary.

BREAK SUPPLY LINE:

1. Trailer brakes should apply.
2. There should be no air loss from trailer.
3. Air from the tractor should:
   1. stop immediately; mandatory on L75 or,
   2. bleed down to between 45-20 P.S.I. , then stop.

NOTE: Under no circumstances should tractor pressure drain below 45-20 P.S.I.

Reconnect supply line and recharge trailer. Rebuild pressure if necessary.

BREAK SERVICE LINE:

No air should escape. Make a full brake application.

1. Trailer brakes should apply immediately and there will be no further loss of air from the service line; mandatory on L75 or:
2. Tractor air will bleed down to 45-20 P.S.I. and then trailer brakes will apply with no further air loss from the service line.

Reconnect service line, charge trailer and rebuild pressure to maximum reservoir pressure.

AT MAXIMUM PRESSURE:

1. Release parking brakes.
2. Shut off motor.
3. Make a full brake application, check for:
   1. air loss less than 4 P.S.I. drop within one minute;
   2. audible air leaks.

START MOTOR AND FAN BRAKES

1. Stop fanning at 80 P.S.I. to see if governor has cut in (needle should start to climb).
2. Continue fanning:
   1. warning device should start operating at 60 P.S.I.;
   2. trailer brakes should apply between 45-20 P.S.I. (L75 must apply at 60 P.S.I.)
   3. parking brakes should apply at 45-20 P.S.I., if plumbed into main reservoir tanks.

REBUILD PRESSURE TO MAXIMUM

1. With parking brakes set, remove wheel chocks.
2. Gently tug test against parking brakes in low gear.
3. Release parking brakes and set trailer brakes with the hand valve. Gently tug test against the trailer brakes in low gear.
4. Move vehicle ahead slowly and make service brake application to check for brake response.