1. Check the Fluid Level:
* First and most important: Check the power steering fluid level in the reservoir. It should be between the minimum and maximum lines. If it's low, add the correct type of power steering fluid (consult your owner's manual). Low fluid is the most common cause of air in the system.
2. Start the Engine and Turn the Steering Wheel:
* With the engine running, slowly turn the steering wheel all the way to the left, hold for a few seconds, then all the way to the right, hold for a few seconds. Repeat this process several times. This will circulate the fluid and help expel any air bubbles. Observe the fluid level in the reservoir; it shouldn't drop significantly. If it does, add more fluid.
3. Listen for Unusual Noises:
* As you turn the wheel, listen for any unusual noises coming from the power steering pump or system. A whining or groaning noise can indicate a problem beyond just air in the lines.
4. Check for Leaks:
* Inspect the power steering hoses, pump, and rack and pinion for any leaks. Leaking fluid can introduce air into the system.
If the problem persists after trying these steps:
* Professional Help: It's likely there's a more serious problem with your power steering system. A leak or a faulty pump are possibilities. Take your Aerostar to a qualified mechanic for diagnosis and repair. Attempting further self-repair without proper knowledge could worsen the situation.
Important Considerations:
* Fluid Type: Use only the power steering fluid specified in your owner's manual. Using the wrong type can damage the system.
* Safety: Always work on your vehicle in a safe, well-ventilated area. Power steering fluid is corrosive. Wear appropriate safety glasses and gloves.
While some vehicles have specific bleeding procedures, the 1991 Ford Aerostar's system generally relies on the simple process of running the engine and turning the steering wheel to remove trapped air. If this doesn't solve the problem, don't hesitate to seek professional assistance.
