Deck 13: Engine Retarders

Question 1

What is another way of saying engine braking?

A) service braking
B) engine retarding
C) driveline braking
D) dynamic braking

Answer 1

engine retarding

Question 2

Which of the following best describes the role of engine braking in a truck braking system?

A) compliments service braking
B) replaces service braking
C) compliments the park brake system
D) replaces driveline braking

Answer 2

compliments service braking

Question 3

Which of the following describes a brake in which the retarding force is the upstroke of the engine piston on its compression stroke?

A) exhaust brake
B) service brake
C) external compression brake
D) internal compression brake

Answer 3

internal compression brake

Question 4

When an internal engine compression brake is actuated, what role does the engine play?

A) power producing pump
B) energy producing compressor
C) energy absorbing compressor
D) torque converter

Question 5

When is the braking efficiency of any engine brake usually at its highest?

A) at idle rpm
B) at peak torque rpm
C) anywhere in torque rise
D) at the highest engine rpms

Question 6

Which of the following types of engine brake uses hydraulic retarding?

A) Jacobs internal brakes
B) Mack Trucks Dynatard
C) Caterpillar BrakeSaver
D) PacBrake

Question 7

When a Jacobs internal engine compression brake is actuated, at what point is cylinder compression dumped into the exhaust circuit?

A) around TDC on compression stroke
B) at the beginning of the compression stroke
C) at the completion of the exhaust stroke
D) gradually throughout the compression stroke

Question 8

When an engine brake is actuated as part of cruise control management, what is the term sometimes used to describe the cruise control system?

A) logical
B) illogical
C) smart
D) auxiliary

Question 9

When a Williams type exhaust brake is fully actuated, which of the following is true of the exhaust flow area through the brake?

A) zero flow
B) minimal flow
C) moderate flow
D) maximum flow

Question 10

What force is used to open the exhaust valves on a typical internal engine compression brake?

A) electro-mechanical
B) electrical
C) hydromechanical
D) mechanical over electric

Question 11

Which of the following can be used by the driver to control the cycling of a typical internal engine compression brake?

A) message request from data bus
B) hydraulics
C) engine rpm
D) mechanical movement of valve train

Question 12

In a typical electronically controlled diesel engine, what force is used to time the hydraulic opening of the exhaust valves in an internal compression type brake?

A) electric solenoid
B) injector train movement
C) valve train movement
D) cylinder compression pressure

Question 13

For a truck driver to actuate an electromechanically-managed internal engine compression brake, all of the following switches would have to be closed EXCEPT:

A) driver dash control switch
B) clutch engaged switch
C) accelerator or fuel control switch
D) service brake application pressure switch

Question 14

When an engine brake is actuated on a current truck diesel engine, what is the maximum fueling permitted?

A) no fuel
B) idle fuel
C) high idle fuel
D) rated speed fuel

Question 15

When 100% engine braking is required of a Cummins Intebrake on a pre-2010 ISX engine, how many solenoids must be energized?

A) one
B) two
C) three
D) six

Question 16

Technician A says that an advantage of Cummins Intebrake on a pre-2010 ISX engine is progressive retarding that options engine braking from one through all six engine cylinders. Technician B says that on this engine, Intebrake manages braking using both of its overhead camshafts. Who is right?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 17

Which of the following is NOT an advantage of a Mercedes-Benz constant throttle valve (CTV) type engine brake?

A) quieter operation
B) braking on both piston upstrokes
C) no camshaft loading during braking
D) braking cycles through entire rpm range

Question 18

From where does cylinder gas blowdown occur during a CVT braking cycle?

A) constant throttle valve
B) exhaust valve
C) intake valve
D) piston rings

Question 19

Technician A says that most current engine brakes use the engine ECM to manage braking cycles. Technician B says that modern engine brakes can perform the majority of the braking requirements of a transport truck. Who is right?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 20

What additional feature does a Volvo EPG offer besides engine braking?

A) lower emissions
B) additional engine power
C) lower exhaust temperatures
D) faster engine warm-up

Question 21

What feature allows some current engine retarders to absorb more horsepower than the engine power specification?

A) reverse flow hydraulics
B) dual stage braking
C) allowing the engine to overspeed
D) engaging the engine fan

Question 22

Which of the following terms describes an engine brake in which both upward strokes of the engine pistons are retarding strokes?

A) single cycle
B) dual stage
C) hydraulic lock braking
D) smart braking

Question 23

Technician A says that most current highway diesel engines use the engine ECM to master control of engine braking cycles. Technician B says that some current trucks option engine braking as part of cruise control and directional stability management. Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B