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?

Accepted Answer

Lifting the front wheels off the ground reduces resistance and allows air to escape more easily. Turning the steering wheel left and right helps to expel air from the system.

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?

Accepted Answer

A restricted high pressure line can cause higher than normal pressure readings in a power steering system because it impedes the flow of hydraulic fluid, leading to increased pressure buildup. Internal leakage, on the other hand, would likely cause a drop in pressure, not an increase.

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 ________.

Accepted Answer

The flow control valve is responsible for regulating the pressure within the hydraulic power steering system. If the highest pressures are greater than 50 PSI of each other, it indicates that the flow control valve is not properly regulating the pressure, leading to inconsistencies.

Question 4

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

Accepted Answer

Integral power steering gears use the power steering fluid in the system for lubrication. This fluid circulates within the system, providing the necessary lubrication for the moving parts to operate smoothly.

Question 5

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

Accepted Answer

Each of the listed factors can contribute to hard steering in a vehicle with a hydraulic power assisted steering system. Low or contaminated fluid can impair the system's function, a slipping drive belt can reduce pump efficiency, and low tire pressure increases resistance to steering inputs.

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 ________.

Accepted Answer

Power steering systems can reach pressures as high as 1500 psi, requiring high pressure hoses to handle the load.

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?

Accepted Answer

The power steering pressure switch is responsible for signaling the computer about the increase in power steering pressures, which in turn can adjust the idle speed to prevent stalling during low-speed turns.

Question 8

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

Accepted Answer

Most electric power steering (EPS) systems use DC brushless motors due to their high efficiency, reliability, and the fact that they do not require brushes, which can wear out and require replacement.

Question 9

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

Accepted Answer

The answer of Electronically controlled variable assist power steering systems...

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?

Accepted Answer

Both technicians are correct. Some electric power steering (EPS) systems operate on the standard 12-volt electrical system found in most vehicles, while others, especially in hybrid or electric vehicles, may operate on a higher voltage system, such as 42 volts, to provide the necessary power efficiently.

Question 11

All power steering pumps have integral reservoirs.

Accepted Answer

Some power steering systems use remote reservoirs that are not built into the pump, but are connected via hoses.

Question 12

Which of the following represent typical power steering pressures?

Accepted Answer

All of the options correctly represent typical power steering pressures under different conditions, illustrating the system's variable pressure based on steering demand.

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.

Accepted Answer

The power steering pressure switch detects increased hydraulic pressure during sharp turns, signaling the powertrain control module to adjust engine speed for better performance.

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?

Accepted Answer

Technician A is correct because some power steering systems, especially those in vehicles that are subjected to heavy use or operate in hot climates, do use external coolers to help maintain the power steering fluid at optimal temperatures, preventing overheating and prolonging the system's life. Technician B is incorrect because not all variable assist systems are electrically actuated; some use hydraulic mechanisms to vary the level of steering assistance.

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?

Accepted Answer

Technician B is correct because different vehicles, even from the same manufacturer, may require specific types of power steering fluid. Using the wrong fluid can cause damage to the system, particularly to the seals, due to incompatibility.

Question 16

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

Accepted Answer

A system flush is necessary after major power steering repairs to remove any debris or contaminants that could damage the new components and to ensure the system operates smoothly with fresh fluid.

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?

Accepted Answer

Both technicians are correct. Lifting the vehicle and turning the steering wheel from stop to stop is a common method to help bleed air out of power steering systems, ensuring the fluid circulates throughout the system and air is expelled.

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?

Accepted Answer

When the pressure is within specifications with the gauge valve closed, it indicates that the pump and pressure regulator are functioning correctly. The low pressure when turning the wheels suggests a problem in the rack assembly, supporting Technician B's diagnosis.

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?

Accepted Answer

Pascal's law states that pressure applied to a confined fluid is transmitted undiminished in every direction throughout the fluid and acts with equal force on equal areas, perpendicular to the container walls.

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?

Accepted Answer

Both statements made by the technicians are correct. Technician A is correct in stating that one advantage of hydraulics over mechanical linkages is that fluid has no fixed shape, allowing it to be easily directed through various components of a hydraulic system. Technician B is correct in stating that hydraulics can multiply the input force, which is a fundamental principle of hydraulic systems allowing them to perform heavy lifting and exerting large forces with relatively small input.

Quiz 118: Power-Assisted Steering Operation and Service