I have been looking for information on the power steering fluid, and not found much.
How often should we change it?
How do we do so effectively to remove all the oil in the system and replace with out leaving air in the system?

Thanks

 

I don't know what the recommended time or milage for changing the fluid is. If it's been a couple of years or if the fluid is discoloured it should probably be changed.
I would just disconnect the p/steering connection at the gear and let the fluid drain into a bucket. Replace the fluid in the resevoir and with the wheels off the ground turn the steering wheel lock to lock about 15-20 times and that should belle all the air out of the system.
Some shops will hook up a machine to change the oil and I guess that gets all the oil out of the steering gear as well. They also have an adapter that fits on in place of the p/steering resevoir cap that attatches to a vacuum pump to eliminate all the air in the system.

 

Actually, I do it a bit different from that. I use a long snout turkey baster to suck out all of the old fluid from the reservior. Then I fill it back to the proper level and cycle the steering, with the front tires off the ground. Turn the wheel from lock to lock 20 times. Then start the engine and do another 20 or so cycles. Once you have done that, suck out the res again and repeat the cycling first engine off, then engine on. Repeat until you get clean fluid out of the res.

And yeah, there really isn't any predetermined service intervals for the power steering fluid, but if it is starting to get brown, it should be changed.