Truck Tractor Air Brake

Question 0

When the compressor is in its. Unloaded cycle

Answer 0

The inlet valves are held open

Question 1

On compression stroke the inlet valve is

Answer 1

Closed and the discharge valve is open

Question 2

The governor controls maximum air system pressure by

Answer 2

Putting the compressor in the unloaded cycle

Question 3

When does an automatic drain valve drain moisture and contamination from the reservoir

Answer 3

When there is any drop in reservoir pressure

Question 4

Air brake antifreeze is used in the air brake system to

Answer 4

Prevent Moisture in the system from freezing

Question 5

Desiccant type air dryers rely on

Answer 5

Beads that adsorb moisture vapor from the air stream

Question 6

Why are single check valves installed on the primary and secondary service reservoirs

Answer 6

To prevent air loss in the event of a failure in the other reservoirs

Question 7

The function of the safety valve is to

Answer 7

Limit air pressure buildup in the event of a governor failure

Question 8

CMVSS 121 states the minimum pressure at which the low pressure warning devices must warn the operator is

Answer 8

60 PSI

Question 9

Nylon airbrake tubing should not be used where it may be exposed to

Answer 9

High temperatures,abrasion and wear, excessive movement

Question 10

The function of the relay valve in the primary brake circuit is to speed up the

Answer 10

Application and release of the primary service brakes

Question 11

I type 24 brake chamber has an area of

Answer 11

24 square inches

Question 12

During normal brake applications, the secondary section of the dual circuit brake valve is applied by

Answer 12

Primary service air pressure

Question 13

The function of the quick release valve in the secondary break circuit is to

Answer 13

Speed up the release of the secondary service brakes

Question 14

The dual circuit brake valve holds it’s inlet and exhaust valves closed

Answer 14

When the valve is in its balanced position

Question 15

What are the 5 air systems on a truck/tractor?

Answer 15

1. Supply
2. Primary service
3. Secondary service
4. Park/emerg.
5. Trailer control

Question 16

What are there 3 major components of supply system?

Answer 16

1. Compressor
2. Dryer
3. Governor

Question 17

When a compressor is building air in system is is said to be in what cycle?

Answer 17

Loaded cycle

Question 18

The purpose of governor is to?

Answer 18

Control compressor cut-in and cut-out pressure

Question 19

The primary brake system is used to supply what brakes.

Answer 19

Drive axle(s) brakes

Question 20

Brake valves are commonly referred to as?

Answer 20

Treadle valve

Question 21

Treadle valves can be either ____ mounted, or _____ mounted?

Answer 21

1. Floor

2. Firewall

Question 22

In treadle valve what system is closest to pedal?

Answer 22

Primary

Question 23

What are two types of brake chambers?

Answer 23

1. Service

2. Spring brake

Question 24

During normal brake application what applies secondary section of the dual-circuit brake valve?

Answer 24

Primary service air pressure.