w210 99 e300td power steering stiff going right
 

My power steering randomly goes stiff when turning right only. I noticed the manual doesn't specify fluid checking or type. Any help?

Mercedes sells a fluid at the dealership that is their recommended power steering fluid. It is sold in 1 Ltr bottles.

Checking the level is easy enough, there is a dipstick built into the cap with lines on it. If it is low, look for a leak somewhere. Sometimes the return line leaks right at the connection to the reservoir. Check the level first though.

steering stiff turning right
 

My 98 E300 has the same problem. I flushed the power steering system with fresh fluid last summer, and that helped for a while (the stuff that came out was black). As the weather got cooler, it started acting up again, so I flushed it again and replaced the fluid with the Pentosin synthetic power steering fluid used in the newer Mercedes models. The dealer recommended the synthetic fluid as something worth trying before buying a new rack. They have had some success using the synthetic fluid to solve W210 steering problems. He said a sticking orbital valve is the problem. My steering is stiff sometimes after the car has been parked for a while, but it is rarely stiff in warm weather. I have also found turning to the left before turning right frees the valve most of the time.

I had the same symptoms in my 2000 E430, and it slowly got worse and worse.

The stiffness only happened when turing to the right, and it eventually got so bad, that you could hardly turn the wheel to the right when manuevering in a parking lot.

My mechanic diagnosed the problem as a bad rack and pinion.

A factory rebuilt unit was about $1,800, and it fixed the problem.

What is the proceedure for the flush? tia

Have you tried the Lucas Power Steering Stop Leak? I'm not sure if it will eliminate the symptoms of this problem but it's supposed to and it did stop a leak on my 87 300D. It may be worth a try. If it doesn't work you can always replace it with something else. The most important thing is to keep the fluid at the proper level and replace it regularly. If you do that you don't need to flush. Just disconnect the low pressure hose and let the fluid drain or suck it out with a MityVac.