geniushanbiao

I have a weird problem with my 07 R350 4matic. It has 75k miles. When I start from cold or after parked for more than 10 minutes everything is fine. However after drive for a while and trying to park into a parking lot or parallel parking, the steering becomes very very very stiff(no assist at all!) when the engine is idling. If I step on the gas it would help. This happens most when I did some highway driving. If only drive local it is most likely fine. I checked the pump and there's no free play on the pulley. The reservoir was replaced not long ago and fluid was flushed out couple times with the fluid got from dealer. I bled the system for many times, too.

I'm wondering if it's the problem with the PS pump or the Y10 solenoid?

Exploded_Muffin

Probably the power steering pump. Just had mine replaced a few weeks ago.

The steering was extremely stiff at idle and really low rpms but once the rpm increases everything is back to normal. Made parking the car or just general low speed manoeuvres a nightmare.

geniushanbiao

Did yours behave stiff at idle right after you start the engine? Mine behaves like right after I start the engine or drive local it has no problem. However after some highway drive it becomes stiff at idle.

taleb659

First step is make sure the fluid is at the correct level and there is no air in the system. Jack the front of the car ensuring both wheels are off the ground. Turn the key to second position and make sure the car is off during this procedure. Have an assistant turn the steering wheel lock to lock 30 times.

As the assistant is turning the wheel monitor the reservoir for any air escaping and ensure the fluid stays at a pretty good level. You do not want the pump to draw any air as this will be very difficult to remove.

If all checks out let me know and then you can proceed to the next step in finding the problem.

galileo55

2007 GL450 steering very stiff at Idle. Much Better/Normal while moving or at higher RPM while stationary in "N".

Checked Steering fluid level. Found it low. Purchased and added Steering Fluid from MB dealership. Drove about 20 miles. Turned a dozen times lock-to-lock left and right. Fluid level stayed good. No improvement.

Some background: This car had a leaky Steering Reservoir "O" Ring. Reservoir was replaced at MB dealership about 9 months ago. Was and still is no longer leaking. Not sure why level dropped at all.

I will try the 30 turns while jacked this weekend as suggested by previous post by taleb659.

In the meantime, any other suggestions to bleed any air that may have gotten in to the system?

Thank you

BILLYTHEC

there was also a recall on a lot of these.
http://repairpal.com/recall/08V682000