1996 Ford Windstar Power steering noise

Letting Ford pwr. Steering pumps growl even for a short period of time ruins them fast, so if you've had the pump make the noise for more than a few minutes, you may need another pump. They are very sensitive pumps; air in the system causes them to go faulty easily.

First the good-case scenario, then I'll provide a bad-case scenario.

Good Case: Make sure the resovoir is full. Let the car rest overnight. Small air bubbles in the system can make the noise, even if the liquid looks "full". What happens when there's too much air in the system is that the pwr steering fluid gets saturated with tiny air bubbles (kind of like when you open a warm 2-liter soda bottle).L all that air gets suspended in the liquid and makes hard work on the pump. Let the car rest overnight. Jack up the front end so there is no stress on the front tires. Without engine running, turn steering wheel lock-to-lock slowly a few times. Keep resovoir full, but beware of turning the wheel causes pressure, and the resovoir may spray out fluid. So turn the wheel slowly. Take about 20 seconds from left-right-left lock-to-lock. Start the engine and immediately turn the wheel extreme left to extreme right (lock-to-lock) without slamming the wheel when it reaches it's limit. In other words, when the steering wheel reaches it's turning limit, turn the opposite direction immediately. Don't turn the wheel too fast. If it takes about 10 seconds from lock-to-lock, that's about the correct turning speed. Do this about 20 times, or until you hear the pump getting more quiet. Shut engine off. Keep vehicle jacked up. Start engine again after 30 minutes or so and repeat lock-to-lock. The secret with hydraulics is patience and no stress on components while bleeding them.

If this doesn't quiet down the pump noise after 4 tries or so, you'll need to replace the pump and try again.

Thus, the bad-case scenario: Replace pump again and bleed system with front end jacked up as explained.

In any case, work with an assistant to ensure that the resovoir always remains full. Have one person start the engine from the driver's seat, and have another person with a small bottle of pwr steering fluid hovering over the open resovoir to immediately replenish any fluid that the pump sucks in to fill up the system. The secret (again) is patience, having the least amount of air bubbles being circulated in the system, and getting the front end jacked up to eliminate stress on the front wheels while they are being turned lock-to-lock.

Oh, and do this with engine idle. The faster the engine is turning, the smaller the little bubbles will be chopped up, and the longer it will take to bleed. Big bubbles are easier to expel than small ones. Keep the engine at idle. Don't rev engine up in efforts to get fluid flowing faster thru system. This is counter-productive.

There is no way to bleed out the rack/pinion. That is automatically accomplished with the fluid flow from the pump and by turning the steering wheel lock-to-lock. Besides, the rack is at the bottom of the system; gravity will tend to pull all liquids to the bottom. Allowing all air to float to the top into the resovoir.

Again, the only way to bleed out some hydraulics is with patience. I've had Fords which I bleed using this system, shut the engine off for +/- 4 hrs, then try again. Shut off engine again for 4 hrs. Try again, and again. Finally, I got all the air out and it got quiet. When you no longer see soda-pop air bubbles floating in the resovoir, the system is without air. If the pump continues making noise. I don't have an answer for you other than the pump is defective. Realize, pwr steering pumps on fords are inherently "noisy". They all make a little noise under pressure. I'm not there to hear your pump, but they are not silent during normal operation.

Final thought: I also bled one Ford by removing all spark plugs, disabling the ignition system, and cranking engine over with starter while turning steering wheel. This allows the pwr steering pump to pump at a slower pace, lessening the chance of cavitation and making small bubbles. Instead, it pushed all the fluid thru the system, allowing the air to escape slowly. Use common sense using this method: Don't overheat the starter motor.