Examkin

Question

Difficulty: MediumSteering Systems

A driver hears a distinct hissing noise from under the hood whenever the steering wheel is held firmly against the steering stop at full lock during a tight turn. Which component inside the hydraulic power steering pump opens to safely divert pressurized fluid and prevent hose rupture under this peak load condition?

  1. A
    Hydraulic proportioning valve
  2. Pressure relief valveAnswer
  3. C
    Thermostatic bypass valve
  4. D
    Shock damping orifice

Answer

The pressure relief valve safely limits peak fluid pressure inside the power steering pump during full-lock conditions.
When the steering wheel is turned completely to full lock, the wheels reach their mechanical limit, stopping fluid flow through the gear. The resulting spike in hydraulic pressure forces the spring-loaded pressure relief valve open, allowing fluid to bypass back into the pump inlet to protect hoses and seals from rupturing.

Step-by-Step Solution

1
Identify the operating condition described in the scenario
The steering system is at full lock (maximum wheel deflection against mechanical stops), causing hydraulic pressure to spike to its maximum threshold.
When the steering linkage reaches its mechanical travel limits, fluid flow through the steering gear is blocked, rapidly driving up system pressure.
2
Determine the protective mechanism designed for peak hydraulic pressure
A spring-loaded pressure relief valve located within the power steering pump flow control assembly opens.
Without a relief mechanism to recirculate high-pressure fluid back into the low-pressure pump reservoir, excessive hydraulic pressure would blow out seals or burst pressure lines.

Key Concept

Hydraulic power steering pump pressure regulation and relief mechanisms
Estimated Time:1m 0s
Rate this question

Topics

Steering Systems

More questions from this topic