Air Brakes and Safety Test Procedures

Vocabulary and technical specification flashcards for Air Brake inspection and systems testing.

Air Governor Cut-In Minimum

$$85\,psi$$

Air Governor Cut-out Maximum

$$140\,psi$$

Air Governor Normal Range

$$110-120\,psi$$

Cut-out Indicator

A purge sound made when the tanks are full of air.

Applied Test Pressure Loss Limit

Not to lose more than $3\,psi$ in $1\,minute$.

Applied Test Verification

Checking and listening to the Brake lines and Diaphragm to hold full pressure during a panic stop.

Low Air Warning Threshold

Light or buzzer activates between $75-55\,psi$.

Emergency Brake Pop Out

The parking brake pops up by the time pressure reaching $30\,psi$.

Stall Test Pressure

Pump the brake pedal until the gauge is under $20\,psi$.

Dead Pedal (Bushing Check)

With the bus in DRIVE and E-Brake held down, fanning from the brake to the gas and back to check for no response.

Interlock Test

With front and rear doors open and transmission in Drive, the bus should not move and should have a dead pedal when the accelerator is pressed.

Brake Adjustment Yard Stop

Letting the bus roll $3-5\,mph$ and pressing the Service Brake to see if the bus pulls to the left or right.

Spring Brake Hold Yard Stop

Letting the bus roll $3-5\,mph$ and applying the Spring Brake to ensure the bus comes to a complete stop.