e320 211 strange power steering problem

[moestavern]

I need a bit help with an annoying PS problem, after about 30-40 minutes driving the power steering stops working, but if I accelerate up to 40-50 mph it comes back on again. Is there a solenoid or speed sensor that could be faulty? My indy can't or won't find the problem as I think he was glad to see the back of my motor which had numerous niggly problems, he found and fixed most but this was a bridge too far. Any ideas would be good.

 

[PhilL]

Sounds a daft question I know, but have you checked the fluid level for the power steering? Had my S211 for six months before I checked it, found it low, topped up with MB fluid, and steering transformed.

The other thing that made a tremendous difference to the steering was changing the upper ball joints (simple job). Still don't understand why it made steering much better, but it did!

Phil

 

[brucemillar]

Disclaimer.....I am not the expert.

The PS pump is belt driven so it either works or it does not. The only factor outside of pump or belt failure? would be fluid level. As previous poster states it is worth a look as a little fluid makes a big difference.

I have recently had to replace the pump on my C240 which exhibited the same symptoms as you describe for a few days then just gave up completely. The pump on my C55 was weeping and noisy. Recon pumps from MB are about £195 for the C-Class. Or £130 from Dronsfield with 6 months warranty.

Long shot.. Check the belt tension and condition. Just in case it is slipping at xx mph.

 

[moestavern]

Thanks for replys guys, thing is that the steering only packs up at 30-35 minutes of driving every day, which indicates to me it has to be a heat thing or as you say it could be the fluid level, will check that tomorrow when cold, easy to do that. The bigger picture is the pump but if it was bust then i would have no PS at all.
Got something to go at now gents
Thanks