There are several ways to determine if your power steering seal is leaking:

1. Fluid leak: A fluid leak under the vehicle or on the ground where you park your car is one of the most obvious signs of a failing power steering seal. The fluid is typically a reddish or pinkish color, and is usually the power steering fluid.

2. Low fluid level: If your power steering fluid level is low, it could be due to a leak in the power steering seal. Check the fluid level periodically and look for any signs of leakage.

3. Whining or groaning noises: If the power steering pump is low on fluid, it can produce a whining or groaning noise when you turn the steering wheel. This could indicate a leak in the power steering seal.

4. Steering difficulty: If the power steering system is low on fluid, the steering may feel stiff and difficult to turn. This could also indicate a leak in the power steering seal.

5. Debris: If the power steering seal is damaged, dirt and debris can enter the system and cause damage to other components. If you notice any debris in the power steering fluid or on the ground under your vehicle, it could be a sign of a leak.

If you suspect that your power steering seal is leaking, it's important to have it inspected and repaired as soon as possible to prevent further damage to the power steering system.