ASE A4 Suspension and SteeringSteering System Diagnosis and RepairMedium
A vehicle with hydraulic power steering exhibits a noticeable 'squeal' or 'chirp' when the steering wheel is turned quickly, especially during cold starts. The fluid level is correct and the fluid appears clean. Which of the following is the MOST likely cause?
- AA restricted power steering return line.
- BInternal wear in the power steering pump.
- CLoose or glazed power steering pump drive belt.
- DAir trapped in the power steering system.
Show answer & explanationAnswer & explanation
Correct answer: C. Loose or glazed power steering pump drive belt.
A 'squeal' or 'chirp' noise, particularly when turning the wheel quickly or during cold starts, is a classic symptom of a slipping power steering pump drive belt. The increased load on the pump when steering quickly or when the fluid is thick (cold) causes the belt to lose traction, resulting in the noise.
Why the other options are wrong
- A. A restricted return line would cause increased pressure, potentially leading to heavy steering or seal leaks, but not a squealing belt.
- B. Internal pump wear typically causes a groaning or whining noise, not a squeal.
- D. Air in the system usually causes a whining or gurgling noise and often leads to inconsistent assist.
Power Steering Belt Squeal
A squealing or chirping noise from the power steering system, especially during quick steering inputs or cold starts, often indicates a loose, worn, or glazed power steering pump drive belt that is slipping under load.
- Caused by belt slipping on pulley.
- Worse under high load (quick turns, cold fluid).
- Check belt tension, condition, and pulley alignment.
Memory trick: Belt Squeals Quickly, especially when cold.