Important: do not reuse any drained power steering fluid, no matter how clean it looks!
On a regular basis, you are supposed to check the power steering fluid for:
- Correct Level: make sure the level is appropriate at all times, just like the oil level in your engine.
- Contamination: if the fluid is milky, brown or has debris you need to flush the power steering system.
Normally, the power steering fluid is translucent, slightly greenish but should be clear. The following photo shows power steering fluid that is long overdue for replacement:
The flushing of the power steering fluid is a rather lengthy process and you will need an assistant to perform the task correctly: anyone who can turn a steering wheel will do. Note: they will be tired at the end of the procedure, buy some treats for them.
As for the duration of the procedure, I suggest putting on a trickle charger to avoid abusing the battery.
The car needs to be raised sufficiently so the front tires do not touch the ground, I strongly recommend jacking up the car horizontally (lifting all 4 wheels), but keeping it low enough so that you can work in the engine bay.
The first thing to do is empty out the power steering fluid reservoir (object B in diagram hereafter) with a baster:
As shown in the photo below, the reservoir has a cap with a steering wheel on it:
You will need to place a large container under the fluid return hose in order to collect the old fluid. Now this is difficult due to the position of the power steering reservoir in the engine bay; so what I did is purchase a 3 foot translucent garden hose and made the hose go through the engine bay to a used oil container underneath. I made the hose go down the engine bay right alongside the radiator, you will need someone to guide the hose from under the engine bay as the hose descends: I was unable to make it go down by myself.
The translucent hose is very important because you need to drain the fluid until it is clear, more on this later. I took a 1 inch garden hose so that the fluid return hose goes right in without any hassles.
Now you need to remove the fluid return house from the reservoir: this hose is attached to part #5 in the following diagram:
There are two tubes attached to the reservoir, the direction of the fluid is shown by the red arrows:
The outbound hose (part #8 in previous diagram) goes to the power steering pump and is the largest of the hoses that are attached to the reservoir. The inbound is the fluid return hose - the one that needs to be disconnected (it's a pain to remove, easy to put on).
Now be careful, although you may have emptied out the reservoir, you can't pull all the fluid out of the reservoir. When you detach the fluid return hose, power fluid will run from the hose and, more importantly, from the reservoir.
Once, you can have really emptied out the reservoir you can plug the reservoir return hose inlet connection because you will need to put some fluid in the reservoir.
Connect the fluid return hose to the garden hose and make sure the bottom of the garden hose goes to the large container ... it will avoid some serious cleaning ...
At this point in time, my engine bay looks like this (the garden hose has white strips on it):
Now, have someone sit at the steering wheel of the car, without touching the brakes
, power the car on with the engine off
In order to do this, press on the Accessory button until the car powers up (about 3 seconds).
Fill the power steering fluid reservoir with new fluid (you can really fill it up to the top, it is going to be emptied out real quick) and have your assistant turn the steering wheel one way until it blocks and the turn the other way until it blocks.
The trick here is to turn the steering wheel at a constant, decent pace: too fast or too slow gave a sort of cavitation and minimized fluid output. When the steering wheel blocks, wait a bit before turning the other way (this allows for the fluid to be pushed out of the system).
As the steering wheel turns, the old fluid will be pushed out through the garden hose and you need to keep the reservoir full at all costs.
Important: this process may consume up to 4L (4qt) of new fluid!
In my case, I really went through 4 bottles. You need to keep some fluid at the end to top off the level (I purchased 5 bottles, although I assume you can manage with 4 bottles).
Continue doing this until the fluid runs clear - hence the importance of having a clear garden hose ...
Remove the plug from the pump reservoir inlet and plug back the hose. Fill the reservoir to normal level, check for leaks.
Turn the steering wheel back and forth twice: add fluid to correct level.
Clear engine bay of any lost fluids, start engine, turn wheels a bit, shut engine down, top off if required.
Check after some driving that the fluid level hasn't decreased, if it has add some fluid and make extra sure there are no leaks.
Important: never turn steering wheel if there is no fluid in the reservoir ... at all ... don't even think of doing it ... never.
Never start the engine if the fluid level is not at normal level. When you first start, there will be a drop in fluid level, guaranteed: the hoses have to fill up with fluid after the purge process!