Originally Posted By: Kestas
The second method is required if you replace components as the pump or rack. It'll flush out the contaminant debris. I also recommend it for the first flush.
The first method is good for maintenance. It'll thin out the wear debris.
Right on!
Seldom is the oil bad in a PS system but often the oil is loaded with contaminants, wear metals, etc. that can cause early wear and later failure. And there is no filter, so the harmful chunks just circulate endlessly and do damage. The turkey baster is better than nothing... but not by all that much if the oil has never had a full change. IMO, an early first change, at around 5K miles, or the addition of an inline PS filter on the return line (Magnefine or equivalent), will go a long way toward a trouble free PS system. If you look at how many rack & pinions get replaced (they are especially vulnerable to hard contaminants which can start leaks).
The break in period change is the most important to get a full flush. After that, the turkey baster is likely fine for keeping the oil fresh (my own estimation) but I think a filter is the best idea because you can install it without dumping all the good oil and it does the job for you.
A filter will extend the life of the oil by reducing the effects of oxidation from certain catalytic metals (like iron and copper) but eventually, the oil will need to be changed.
My full flush method:
1) Suck the reservoir dry with your baster.
2) Disconnect the return hose at the reservoir (or you can drain the reservoir this way if it's easier. FYI, you can disconnect the return hose at any point in the system. With my F-150, the PS oil cooler on the return circuit is down on the chassis and makes a GREAT place for this.
3) Run an extension hose from the return hose to a container large enough for at least a couple of quarts. I use a clear hose so you can see the clean oil.
4) Cap off the fitting on the reservoir so it will hold oil again.
5) Fill the reservoir.
6) Start the engine and let the oil flush through the system while filling the reservoir. Cycle the steering at least one time lock to lock to purge any oil oil there in the spool valve. Be sure to keep the reservoir full so you don't aerate the system. It's not a disaster if you do (with the systems I know about) but it saves time purging the system later.
7) Reconnect all the hoses in the correct way and refill the reservoir.
8) Start the engine and cycle the steering lock to lock a couple of time to purge any air, then recheck oil level.
9) Clean up any oily mess on the components and recheck the oil level after the first drive.
PS to Vikas: The return line is not more likely to leak after you remeove it than if the dealer or anyone esle did it for any reason... unless the person doing it makes a mistake. For most return hose, it will be just a hose clamp. Simple enough to get right. Return pressure is low.
