C - Truck/Tractor Air Brake System Components - Part A Flashcards
When an air brake compressor piston is on its compression stroke, the inlet valve:
Is closed and the discharge valve is open.
When the compressor is in its unloaded cycle:
The inlet valves are held open.
The governor controls maximum air system pressure by:
Putting the compressor in the unloaded cycle.
The automatic drain valve drains moisture and contamination from the reservoir when:
Any drop in reservoir pressure.
Air brake antifreeze is used in the air brake system to:
Prevent moisture in the system from freezing.
Desiccant type air dryers rely on:
Beads that absorb moisture vapour form the air stream.
Single check valves are installed in the inlet line to both the primary and the secondary service reservoirs because they:
Prevent air loss in the event of a failure in the other reservoirs.
The function of the safety valve is to:
Limit air pressure buildup in the event of a governor failure.
CMVSS 121 states the minimum pressure at which the low pressure warning devices must warn the operator is:
60 psi (414 kPa).
Nylon air brake tubing should not be used where it may be exposed to:
High temperatures, abrasion and wear, and excessive movement.
In the released position, the inlet/exhaust valves of the dual-circuit brake valve are in the following condition:
Inlets are closed and exhausts are open.
The dual-circuit brake valve holds its inlet and exhaust valves closed:
When the valve is in its balanced position.
The function of the relay valve in the primary brake circuit is to speed up the:
Application and release of the primary service brakes.
When the dual-circuit brake valve delivers 20 psi (138 kPa) of primary service application pressure, a relay valve with a cracking pressure of 2.5 psi (17.2 kPa) reacts by sending:
17.5 psi (120.6 kPa) to the primary brake chambers.
A type 24 brake chamber has an:
Area of 24 in squared.
