Air brake Quiz #1 Flashcards
Reaction time maybe defined as:
the time it takes for the driver to push the treadle valve.
the time it takes for the vehicle to stop after the treadle valve has been depressed.
the time it takes for the air to reach the brake chamber from the treadle valve.
the time it takes for the driver to adjust the brakes.
the time it takes for the driver to push the treadle valve.
Brake lag is:
the time it takes for the driver to push the treadle valve.
the time it takes for the driver to adjust the brakes.
the time it takes for the vehicle to stop after the brakes have been applied.
the time it takes for the air to reach the brake chamber from the treadle valve.
the time it takes for the air to reach the brake chamber from the treadle valve.
If the speed of a truck were doubled; the amount of work the brakes would have to do would be:
8X
the same as before.
4X
2X
4X
A vehicle requires 400 hp (149kw) to accelerate from 0 to 100Km/hr in 60 seconds. To bring the same vehicle to a complete stop in 6 seconds, the braking system must develop:
200 hp (149kW).
400 hp (300kW).
2000 hp (1.49MW)
4000 hp (3.00MW).
4000 hp (3.00MW).
To protect the air brake system from excess pressure, the pressure relief valve will relieve at:
150 p.s.i.
300 p.s.i.
120 to 130 p.s.i.
175 p.s.i.
150 p.s.i.
Moisture forms in the reservoirs by:
evaporative cooling.
pressurizing the air.
evaporation.
condensation.
condensation.
The standard for pressure in an air brake system in Alberta is:
175 p.s.i.
120 – 130 p.s.i.
150 p.s.i.
100 – 120 p.s.i.
120 – 130 p.s.i.
Normal lag time on a well maintained air brake system is approximately:
.7 seconds.
.3 seconds.
1.3 seconds.
.25 seconds.
.3 seconds.
Most air brake valves in the released position will have:
both valves open.
both valves closed.
the exhaust valve open.
the inlet valve open.
the exhaust valve open.
The coefficient of friction maybe defined as:
how hard the brake linings are.
how much heat the linings and drums produce.
all of the above.
the resistance to movement between the shoes and the drums.
the resistance to movement between the shoes and the drums.
Very high temperatures cause the numerical value for the coefficient of friction of the brake pad to:
improve.
increase.
decrease.
remain the same.
decrease.
One disadvantage air brake systems have is that:
braking effort is affected by small leaks in the system.
the system must be bled when connecting or disconnecting the system.
air brake components are more expensive than hydraulic components.
there is always some brake lag.
there is always some brake lag.
A driver makes a 40 p.s.i. application. If the vehicle is equipped with air brake chambers that are type 30; each chamber will exert:
1200 lbs. of force.
120 lbs. of force.
3600 lbs. of force.
2400 lbs. of force.
1200 lbs. of force.
The part of the air brake system that the driver uses to regulate the air pressure when applying the brakes, is the:
brake chamber.
brake valve.
slack adjuster.
governor.
governor.
The inventor of the air brake is credited as being:
Westinghouse.
Meritor-Wabco.
Haldex.
Bendix.
Westinghouse.
A properly adjusted brake will have:
a slight amount of drag.
2 inches of travel with no drag.
1 inch of travel with no drag.
1 inch of travel with a slight drag.
1 inch of travel with no drag.
Brake drums are marked with:
a minimum thickness.
discard circumference.
an out of round spec..
a maximum diameter.
a maximum diameter.
One important rule when working on the foundation brake system, is to:
avoid inhaling brake dust.
clean brake shoes thoroughly with compressed air.
watch for released springs.
always replace drums.
avoid inhaling brake dust.
Using brake lining with a GAWR that is too low can result in:
brake fade.
decreased stopping distance.
no effect on the braking.
greater brake application pressure.
brake fade.
Air brake systems are usually referred to as:
forward acting.
single servo.
non-servo.
duo-servo.
non-servo.
Brake fade maybe defined as:
brake slippage when below freezing.
brake slippage when they are overheated.
brake grabbing when they are overheated.
brake slippage due to thin linings.
brake slippage when they are overheated.
The component that provides support for most of the components in the foundation brakes is called:
brake plate.
brake foundation.
brake drum.
brake spider / backing plate.
brake spider / backing plate.
Brake travel is measured between:
the brake shoe and drum.
the brake chamber diameter.
the brake shoe and the drum.
the brake chamber and slack adjuster.
the brake chamber and slack adjuster.
When we look for a 90° angle, we are looking for that angle between:
the brake shoe and drum.
the brake spider and slack adjuster.
the brake chamber and s-cam.
the brake chamber and slack adjuster.
the brake chamber and slack adjuster.
