Deck 118: Power-Assisted Steering Operation and Service

Question 1

Two technicians are discussing the proper procedure for bleeding air from a power steering system. Technician A says that the front wheels of the vehicle should be lifted off the ground before bleeding. Technician B says that the steering wheel should be turned left and right with the engine off during the procedure. Which technician is correct?

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

Answer 1

Both technicians A and B

Question 2

A power steering pressure test is being performed, and the pressure is higher than specifications with the engine running and the steering wheel stationary in the straight ahead position. Technician A says that a restricted high pressure line could be the cause. Technician B says that internal leakage inside the steering gear or rack and pinion unit could be the cause. Which technician is correct?

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

Answer 2

Technician A only

Question 3

When pressure testing an hydraulic assisted power steering system, the highest pressures were greater that 50 PSI of each other. This indicates a problem with ________.

A)The pump vanes
B)The flow control valve
C)A defective hose
D)The pump rotor

Answer 3

The flow control valve

Question 4

Integral power steering gears use ________ for lubrication of the unit.

A)Power steering fluid in the system
B)SAE 80W-90 gear lube
C)Molybdenum disulfide
D)Chassis grease (NLGI 2)

Question 5

What can cause hard steering on a vehicle equipped with a hydraulic power assisted steering system?

A)Low or contaminated power steering fluid
B)Slipping power steering pump drive belt
C)Low tire pressure
D)Any of the above

Question 6

High pressure hoses have to be used on the high pressure side of the power steering system because pressures can reach as high as ________.

A)750 psi
B)1500 psi
C)200 psi
D)2500 psi

Question 7

Some vehicles are equipped to signal the computer whenever the power steering pressures increase so the idle speed can be increased to prevent stalling during turns at low speeds. What component signals the computer?

A)Flow control valve
B)Power steering pressure switch
C)Rotary Valve
D)Pressure relief valve

Question 8

What type of motor is used in most electric power steering (EPS) systems?

A)Stepper
B)DC brushless
C)DC capacitor start
D)AC brush type

Question 9

Electronically controlled variable assist power steering systems vary the amount of boost by ________.

A)Changing the flow of fluid through the steering gear
B)Varying the pump output orifice size
C)Speeding up or slowing down the power steering pump
D)Bypassing some of the fluid back into the reservoir

Question 10

Two technicians are discussing electric power steering (EPS) systems. Technician A says that some systems operate on 12 volts. Technician B says that some systems operate on 42 volts, such as on some hybrid electric vehicles. Which technician is correct?

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

Question 11

All power steering pumps have integral reservoirs.

Question 12

Which of the following represent typical power steering pressures?

A)Less than 150 psi when straight ahead
B)Over 750 psi when slowly maneuvering a parking lot
C)About 450 psi when cornering
D)All of the above are correct

Question 13

A power steering pressure switch sends a signal to the powertrain control module, indicating higher engine speed is needed during sharp cornering at slow speeds.

Question 14

Technician A says that some power assist systems use an external cooler for the power steering fluid. Technician B says that all variable assist systems are electrically actuated. Who is correct?

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

Question 15

Technician A says that all vehicles from the same manufacturer use the exact same power steering fluid. Technician B says that some fluids may be incompatible with system seals. Which technician is correct?

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

Question 16

A system flush is required when any major power steering repair is performed.

Question 17

Technician A says that lifting the vehicle and turning the steering wheel may help bleed air out of some systems. Technician B says that if this procedure is used, the wheels should be turned from stop to stop. Which technician is correct?

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

Question 18

A power steering pressure gauge is being used to diagnose a system problem on a rack and pinion system. When the wheels are turned all the way left, a pressure reading less than specification is found. When the gauge valve is closed, the pressure reading is within specifications. Technician A says that the pump pressure regulator is bad. Technician B says that there is a problem in the rack assembly. Which technician is correct?

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

Question 19

What law states that pressure on a confined fluid is transmitted equally in all directions and acts with equal force on equal areas?

A)Watts' law
B)Martin's law
C)Pascal's law
D)Newton's law

Question 20

Technician A says that one advantage of hydraulics compared to a mechanical linkage is that fluid has no fixed shape. Technician B says that hydraulics offer the opportunity to multiply the input force. Which technician is correct?

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

Question 21

Technician A says that the current trend is to use remote power steering fluid reservoirs. Technician B says that using a remote reservoir allows for a more compact power steering pump assembly. Which technician is correct?

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

Question 22

How much effort is typically required to turn the steering wheel on vehicles with power steering?

A)10 lbs. or more
B)0.5-1.5 lbs.
C)2-3.5 lbs.
D)5-7 lbs.

Question 23

What is the maximum pressure a power steering pump provides during low speed cornering?

A)500 psi
B)250 psi
C)1400 psi
D)90 psi

Question 24

Which statement is TRUE regarding the flow control valve on a power steering pump?

A)It uses a variable orifice to control pressure
B)It is located at the pump outlet
C)Both A and B
D)Neither A nor B

Question 25

Which type of variable effort steering design uses a variable bi-directional magnetic rotary actuator built into the steering rack?

A)SSS
B)Magnasteer
C)EVO
D)TFE

Question 26

What input(s) do/does the Magnasteer system use to determine the amount of power steering assist needed?

A)Mass airflow sensor
B)Wheel speed sensor
C)Both A and B
D)Neither A nor B

Question 27

The steering torque sensor in an electric power steering system senses ________.

A)Steering wheel torque
B)Steering wheel direction
C)Both A and B
D)Neither A nor B

Question 28

If the steering column of an electric power steering system vehicle is replaced, what may have to be re-learned by the electric power steering control module?

A)Lock-to-lock distance
B)Vehicle toe-in
C)Turn signal cancel trigger
D)Torque sensor zero

Question 29

The electrohydraulic power steering pump provides hydraulic power to the steering gear and ________.

A)Valve lifters
B)Cooling fan clutch
C)Hydraulic level control system
D)Brake booster

Question 30

A replacement power steering pump will come with the pulley already installed.