Flushing ps fluid out on 2010 cls 350 cdi

[IFFY100]

Is it a good idea go flush the ps fluid out?

If so, Im thinking of disconnecting the the fluid return line and moving steering left to right to flush all old oil out?

Unless is there a better way of doing this?

 

[DSM10000]

Is it a service item?

I have never known of anyone draining and replacing PS fluid unless a rack was changed.

Also, if draining probably best to have the front of the car raised to help turn the steering with the engine off, unsure how the pumps take to being run dry.

 

[IanW]

Personally, I think it is a good idea to replace the ps fluid. After ~100K miles the steering became a little notchy and less than smooth. A flush/replace restored the smoothness. And again a couple of months ago at 190K miles. The stuff that comes out is black, the replacement is green.
My preferred method for a flush is to empty the reservoir with a turkey baster with the engine off; turn the steering lock-lock repeatedly, periodically emptying the reservoir until no more fluid is being expelled from the rack. Then refill the reservoir with clean fluid, start the engine & turn lock-lock until all the air is expelled from the system. Top up and repeat until no more fluid needed, no more air expelled.
Provided this is done with the front wheels in the air, the whole pump/rack system is unloaded & unpressurised so that wear is minimal. There will still be some fluid in the system at all times that will continue to lubricate.
After a couple of weeks I repeat the process to get anything that wasn't dislodged the first time.
Obviously, this process won't work well on electrically assisted systems...
Ian.

 

[Petrol Pete]

I did mine the 'turkey baster' way at 110K miles , I just syringed fluid from the expansion tank drove it around and syringed it many times until it was perfectly clear. NOT the ideal way as you use about 3 litres of fluid (I had my reasons for doing it this way ) IIRC the rack holds about a litre.

The fluid that came out of mine was dirty black, watery and had a 'particular' smell to it. there is a pump and a valve body in there , new fluid can only be a good thing. On my steering rack there appears to be no replaceable filter, so new fluid is the next best thing.

PS the internet has many videos on the flush process

 

[IFFY100]

I will go with the method stated above. Thanks