Mazio S.

Hi,
I noticed a pool of fluid under my car last week. After starting the car, I noticed the "screeching" sound from the steering wheel and obviously the difficulty in turning the wheel. I checked the PS (power steering) fluid level and it was very low. I then filled it up until i could tend to it. Later on, I checked under the car and around the PS reservoir, but could not tell where it was leaking from. After some research online, I thought it might be the "O" ring from the reservoir to the pump. I should add now, that I had changed the PS pump and reservoir almost 2 years ago and no issues until last week. So, I bought a new "O" ring from the dealer along with a new C clip. I changed them both and filled it with the MB PS fluid last night. This afternoon after coming home I checked and the fluid level was low once again. I also noticed a little PS fluid on my garage floor. I checked around the connection of the reservoir to the pump and did not notice any fluid. How else can I troubleshoot this? without having to change the PS pump again or worse, I hope it is not the steering rack itself which is damaged. Any help is appreciated, Thank you.

2003 ML 350
235K miles

Maj. Dundee

You must replace the reservoir, which probably has a torn membrane, along with a new o-ring.

After replacing the reservoir and filing it, DO NOT START THE ENG. you must raise the two front wheels off the ground and turn the steering wheel all the way to the left and then all the way to the right numerous times until there are no more bubbles. Helper needed to watch reservoir.

Mazio S.

Hi,
I did get a new reservoir tank and O ring but before changing I looked underneath to see if I could find where it is leaking from. After cleaning it, I noticed there was fluid leaking from near the steering rack and pinion. I have attached some pictures. How can I located the leak? And how can I change the seal on the bolt on the end of that shaft?


I checked the output line going to the rack and the return line to the cooler as well. I do not think it is leaking from there.


There was some fluid leaking from this seal.

Maj. Dundee

Buy a couple of cans of Brake Cleaner and spray the entire rack. Then hose it down and let dry.

Have someone start the eng. and turn the steering wheel back and forth while you look at the rack for location of leak.

Mazio S.

i will be taking care of it this weekend. I have a question, the part where the High pressure hose attaches to the pump it’s self, is that part supposed to move? I checked mine this morning and it’s moving when I tried to move the line itself. I have attached a picture (red arrow) Please let me know, in which case I’ll have to order the pump ASAP. Thank you.

IgorE350

Any luck of finding the leak?