Date registered: Jul 2006
Vehicle: 1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
Location: NW Arkansas, La Jolla CA, Hong Kong
Mentioned: 6 Post(s)
Quoted: 136 Post(s)
What I have found..
I don't know about the W164 steering compared to the W163 steering, sorry.
On the "o-ring" replacemewnt - most DIY's also chose to order a new "c-ring" which is a steel clip ring which holds the reservoir. First, good to have a spare c-ring in case you drop the original during removal. 2nd, most expereince3d MB mechanics replace the c-ring since the stampled steeel part will lose some of its original holiding strength with a couple of removals.
Also , you will need MB "power steering oil" (about USD$9 per qt) to top off after replacement. Takes about .75 of a qt, most people buy 2 qts to have some in the garage. Best to use original MB p/s/ oil as not to mix different typer fluids in the power steering system.
If you are also replacing the reservoir, you can use the color caps from the new reservoir to cap off the old fittings on the old reservoir to help keep the mess factor down.
Keep the beat !