Air Break Checks Flashcards
Secure Vehicle
Parking brakes on, buttons out, wheels blocked or chocked.
Defect is: if the truck moves.
Low air pressure warning [light/buzzer]
Button in, key on, start at 90 psi, pump brakes until warning light comes on [must be before 55 psi].
Air pressure buildup of time
Engine on, parking brakes off. Start with air pressure at 80 psi, time from 85 psi to 100 psi. Must do it in two minutes or less with RPM between 600 and 900. The defect is: if it took longer than two minutes.
Air loss rate.
Engine off, parking brake off, start at 90 psi, all the brake pedal down for one minute and say: haven’t lost more than four psi:. Defect is: if you lost more than four psi. Turn push hold
Air compressor governing settings
Button in. Cut out pressure happens when the air dryer sounds off [125 psi]. Cut in pressure 25 psi less than 100 psi. [Needles on the gauge will go up]. Defect is: if cut out pressure is greater than 145 psi and cut in pressure is less than 80 psi.
Tractor [towing vehicles] protection valve
Red button out, yellow button in, remove the blue line [service] from the trailer. Place it by the drivers door. Step on the brake pedal and listen. Should hear no air. Defect is: if air exhaust from the tractor service glad hand.
Auto application function of the trailer brakes
Charging the trailer-push the red button in, count to five, pull the red button out, should hear the brakes coming on [air gushing from the trailer]. Defect is: if the trailer brakes do not apply [come on].
Spring [parking/emergency] brakes [verbal only]
Vehicle on, remove wheel blocks/chocks, yellow button out, Red button out. Place in first gear, give gentle power, vehicle should not move. Defect is: if vehicle moves while parking brake is applied.
Drain air tanks
Find the wet tank, pull the cord, count to five and say “no moisture or contaminants” [Should not see any moisture or contaminants]. Defect is: when drain valve fails to function properly.
Brake adjustment
Button in, parking brakes off, air brakes 90-100, check size and pushrod travel of the brake chamber [type 24-1 3/4], or brake pedal down and measure. Defect is: if applied pushrod stroke exceeds the adjustment limit of the brake chamber.
Safety defects
If a major defect [safety] is found report the condition to the operator in writing and take the vehicle out of service. Defect is: if it was not reported in writing and was not taken out of service.
