Have a 07 R350 4matic with 74k miles. The power steering pump is losing some power when idling so I think the pump is on its way out. Already replaced the reservoir and bleeded the system but doesn't seem to help. Using mercedes power steering fluid. It seems to be a pretty common issue with W251 and the replacement pump is pretty expensive(I don't want any aftermarket parts...). I'm wondering anybody tried to rebuild the pump rather than replacing?

 

Anything can be rebuilt if you can find the parts, have the tools and know how.


A reman. is around $200 but I would look for a reputable brand (not A-1 Cardone) if I went that route. New should be around $450

 

I think it should not be difficult to find out how since ps pump is not that complicated. Problem is I can't find the parts...