Truck Tractor Air Brake Flashcards
(22 cards)
caution must be exercised when working around spring break equipped vehicles because
Spring breaks contain large powerful springs
Spring brake Chambers apply and hold a parking brake application
Without air pressure
Air supply for parking emergency brake operation flows through a double check valve so that the emergency brakes will
Not apply if either service reservoir air pressure is lost
The function of the park control valve is to provide manual
And automatic control of all the parking/emergency brakes on the unit
A quick release valve is often used in parking/emergency brake circuits to provide quick
Application of the spring breaks
An anti-compounding double check valve is often used in parking/emergency brake circuits to
Release the parking/emergency brakes when the service brakes are applied
some truck/tractor units are equipped with a spring break valve that
Allows the spring breaks to modulate application if primary service reservoir air pressure is lost
A relay valve used in parking/emergency brake circuits that use spring break valves to ensure that the spring breaks
Apply and released quickly
The purpose of the trailer supply line is to transmit air pressure
To charge the trailer reservoirs
The purpose of the trailer service line is to transmit air pressure
To apply and release trailer service brakes
The purpose of the trailer brake control valve is to allow the operator to
Independently control trailer service brakes
Tractors equipped with the bobtail proportioning relay valve will reduce
Primary application pressure when the tractor is not towing a trailer
The brake light switch is a normally
Open switch that is closed by primary or secondary service pressure
Spring brakes are _____ applied, and _____ released
Spring
Air
The purpose of a quick release in the spring brake circuit valve is?
To apply spring brakes quicker
The purpose of park control valve is to?
Direct airflow to and from the spring brake chambers
What is the purpose of a anti-compounding double check valve?
To prevent the brakes from being applied when the spring brakes are applied
What is purpose of tractor protection valve?
To prevent air from being sent out trailer service line in the event that the supply line has become disconnected
The trailer service line draw air from where?
Which ever of following has highest pressure being applied:
- Primary side of treadle valve
- Secondary side of treadle valve
- Trailer hand valve
What are two ways to check for properly adjusted brakes?
Applied push-rod/slack angle between 90-95 degrees
Push rod stroke has to be less the max set by manufacturer
The purpose of trailer hand control valve is to allow?
Operator to independently control trailer service brakes
The brake light switch is normally in what position?
Open
It is closed by primary or secondary service pressure
