SL55/63/65/R230 AMG: Power Steering stiffens with SL600 (2004)
Thread Starter
Junior Member
Joined: Aug 2009
Posts: 32
Likes: 0
From: Middlesex, London, UK
1975 Mercedes 350SL V8 (just sold the SL600)
Power Steering stiffens with SL600 (2004)
Hi all.
After frantically getting my car back onto the road after a series of problems, I have another one.
When car is stationary, the power steering is very light. When the car is in motion (e.g. turning r going round corner, or overtaking) the steering doesnt feel very nimble. It feels slightly heavy. When I stop the steering is super-light again.
I have checked all round but there is no sign of any leaks on the floor. I have checked my power sterring fluid reservoir & it is full of right levels of fluid.
Any ideas what the problem could be before I make an expensive call to the Merc garage?
Many thanks,
After frantically getting my car back onto the road after a series of problems, I have another one.
When car is stationary, the power steering is very light. When the car is in motion (e.g. turning r going round corner, or overtaking) the steering doesnt feel very nimble. It feels slightly heavy. When I stop the steering is super-light again.
I have checked all round but there is no sign of any leaks on the floor. I have checked my power sterring fluid reservoir & it is full of right levels of fluid.
Any ideas what the problem could be before I make an expensive call to the Merc garage?
Many thanks,
Thread Starter
Junior Member
Joined: Aug 2009
Posts: 32
Likes: 0
From: Middlesex, London, UK
1975 Mercedes 350SL V8 (just sold the SL600)
Surely not? The Power steering pump is brand new Mercedes Part. It was fitted in February by seller's mechanic. The Mercedes Service Centre confirmed it was a new ps pump kit. The seller paid £1000 out his own pocket to sort it and since having this fixed I have never encountered a problem up until last saturday when it feels heavy to steer. If the pump was dieing sure there would be a leak - but there is no sign of any leak.
Im wondering whether a sensor has stopped working, or whether a compression pipe is blocked?
Im wondering whether a sensor has stopped working, or whether a compression pipe is blocked?
Last edited by mramo; May 12, 2010 at 04:16 PM.
Senior Member
Joined: Feb 2009
Posts: 280
Likes: 8
From: Sarasota FL
2020 E450 Wagon
The pump just supplies hydraulic pressure. If the steering effort was high at low engine speeds a pump could be the problem. A electronically controlled valve on the the steering rack controls the steering effort. With the problem at higher engine speeds and with clean fluid and the filter in good shape, you likely have a control valve or control unit mucking up.
An afterthought. The power steering system can be difficult to bleed. Air can get trapped in the system and cause steering effort and noise issues. You can try to bleed the system manually by raising the car, and with the engine off, turning the steering wheel lock to lock 20 to 30 times.
An afterthought. The power steering system can be difficult to bleed. Air can get trapped in the system and cause steering effort and noise issues. You can try to bleed the system manually by raising the car, and with the engine off, turning the steering wheel lock to lock 20 to 30 times.
Thread Starter
Junior Member
Joined: Aug 2009
Posts: 32
Likes: 0
From: Middlesex, London, UK
1975 Mercedes 350SL V8 (just sold the SL600)
I just found out why the power steering stiffens up when driving. The ECU apparently learns your driving style which may force resistance when driving regular at faster speeds (steering lightens when car is stationary). The steering lightens when driving smoothly, with relaxtion after several weeks. They call it progressive steering.
