Cold weather low on Power Steering Fluid
 

2004 e53 m54 3.0l

On one cold morning, started the truck and heard this weird noise.
Seems like the power steering pump. Then I checked the PS reservoir , I'm a bit low on fluid, so I topped it off with redline ATF / started the truck again / turned the wheels max left and right. And the weird noise was gone !


As a precaution I will replace the PS return/suction hose and clamps, bleed the PS system.


Anything else?6

Before doing anything other than adding fluid, I suggest cleaning off any fluid on anything power steering related and then drive it. Check the fluid level frequently and check to see if you can confirm the source of the leak(s) before any other action.

With the exceptions such as water and milk, most liquid contracts when the temperature drop.

Replace the reservoir at the same time. It has a built in filter in it. Since you are getting messy with the hoses anyway...