Brakes

Question 1

Air brake operating system pressure for safe operation is between ____.

Answer 1

90 and 120 psi.

Question 2

The secondary delivery system of the dual circuit air brake system supplies air to the ____ service circuit

Answer 2

front axle

Question 3

The primary delivery system supplies air to the ___ service circuit.

Answer 3

rear axle

Question 4

The left gauge indicates the ____ air brake system pressure

Answer 4

front (secondary)

Question 5

The right gauge indicates the _____ air brake system pressure.

Answer 5

rear (primary)

Question 6

In the event air brake system pressure drops below approximately ____ a warning buzzer and light will come on.

Answer 6

65 psi

Question 7

As soon as system air pressure increases past _____, the warning light and buzzer will shut-off.

Answer 7

65-75 psi

Question 8

When applying the brakes it is recommended that a firm, constant pressure be applied to the brake pedal as opposed to “___” the brake pedal.

Answer 8

pumping

Question 9

The apparatus dual circuit air brake system has a quick buildup feature that allows the pressure to be built up in the ____ section ____ to enable release of the parking brakes before the pressure in the front (secondary) section is adequately charged.

Answer 9

rear brake (primary) / first

Question 10

In an emergency situation, operator discretion must be used as to the need to operate the apparatus when there is less than ___ air pressure in both brake circuits.

Answer 10

90 psi

Question 11

Use extreme caution when operating the vehicle with either air brake section charged to less than ___ or property or personal injury could result.

Answer 11

60 psi

Question 12

The antilock braking system (ABS) automatically applies and releases the brakes during _____ applications to prevent ____.

Answer 12

low traction or panic brake / wheel lock-up

Question 13

There is ____ ON or OFF switch for the ABS.

Answer 13

no

Question 14

When the ABS applies the Jacob’s Engine Brake is automatically _____.

Answer 14

deactivated.

Question 15

The parking brake circuit is intended to hold the vehicle in a parked position only and should ___ be used for normal driving.

Answer 15

NEVER

Question 16

If air pressure is lost in the rear (primary) service brake section, the spring brakes will be modulated by pressure from the _____ allowing a few brake applications before the spring brakes are automatically applied.

Answer 16

secondary reservoir

Question 17

If air pressure is reduced to approximately ____ in both systems, the spring brake valve will automatically apply.

Answer 17

40 psi

Question 18

The auxiliary front wheel lock feature uses air brake system pressure to keep the ____ applied.

Answer 18

front brakes

Question 19

It is used to augment the rear spring parking brakes in the event the rear parking brakes cannot hold the apparatus on a ___.

Answer 19

steep incline.

Question 20

The Jacob’s engine brake (Jake Brake) is a device, which uses the energy of the engine compression to provide ____.

Answer 20

vehicle retardation.

Question 21

The engine brake converts the engine to an ___ to reduce vehicle speed.

Answer 21

energy-absorbing device

Question 22

This is accomplished by a hydraulic circuit that ___ near the end of the compression stroke.

Answer 22

opens the exhaust valves

Question 23

Jake brake controls consist of

Answer 23

A three-position selector switch.
An on/off switch to activate or deactivate the system.
A throttle sensor.

Question 24

Diesel engines have substantially ___ effect upon vehicles than do gasoline engines

Answer 24

less retarding

Question 25

This is due to lack of ____ in the diesel intake manifold.

Answer 25

restriction

Question 26

There is ___ time limit with respect to the operation of the Jake brake. The engine’s cooling system will continually ____ the heat generated by its continual use.

Answer 26

no / absorb and dissipate

Question 27

The engine brake reacts quickly; it will activate or deactivate in less than ___ of a second.

Answer 27

1/4

Question 28

Do not engage the Jake Brake on ____. The additional braking effort on the drive wheels (duals) can cause them to lock up which could result in an uncontrollable skid.

Answer 28

wet streets

Question 29

Do not engage the Jake Brake during ___. This practice causes undesirable retardation, possible engine and component damage, and engine stalling.

Answer 29

pumping operations