Originally Posted by BlackDesertTango
If the fluid is dirty, your power steering pump will appreciate the new juice. It's very easy to do and there is a step-by-step DIY on the forum which I used to do mine.
Power steering pump failure is almost always caused by past due fluid.
BMW likes to market fluids as long-life or lifetime fluid-its up to you to make the decision to believe that.
I've owned at least 8 cars that had hydraulic power steering. I've had the shop manuals for everyone and the owner’s manuals too. Nowhere have I've ever seen where the manufacturer mandates a periodic power steering fluid change, so don't go trying to loop BMWs lack of recommended power steering change into the "lifetime fluid" crap debate. BMW recommends 100,000 mile changes for transmission, diff, and coolant right in the maintenance booklet that comes with the set of owner’s manuals.
That said, it’s not a bad idea to change the power steering fluid, but it is not mandated by the manufacturer.