ASE A4 Suspension and SteeringSteering System Diagnosis and RepairMedium
A technician is diagnosing a power steering system leak. After cleaning the system thoroughly, a black, oily stain reappears around the connection point between a high-pressure hose and the power steering pump. The hose appears to be correctly tightened. Which of the following is the MOST likely cause of the leak?
- AThe high-pressure hose itself has a pinhole leak.
- BA damaged O-ring or sealing washer at the hose fitting.
- CThe power steering cooler is corroded.
- DThe power steering pump shaft seal is leaking.
Show answer & explanationAnswer & explanation
Correct answer: B. A damaged O-ring or sealing washer at the hose fitting.
A leak at a connection point, even when tightened, strongly suggests a compromised seal. The O-ring or sealing washer is designed to create a leak-proof barrier at these threaded connections and is a common failure point.
Why the other options are wrong
- A. A pinhole leak in the hose would be along the hose body, not directly at the fitting where it connects to the pump.
- C. A corroded power steering cooler would cause a leak in the cooler itself, which is typically located separately from the pump-to-hose connection.
- D. A pump shaft seal leak would typically appear around the pump shaft itself, not specifically at the hose connection.
Power Steering Hose Leak Diagnosis
Identifying the source of a power steering fluid leak requires careful inspection, often focusing on connection points and hose integrity.
- Leaks at fittings often indicate seal (O-ring/washer) failure.
- Leaks along the hose body suggest hose degradation or damage.
- Pump leaks occur at shaft seals or housing gaskets.
- Fluid type and color can sometimes indicate the component type or age.
Memory trick: Seals Stop Seepage Seriously.