Gentlemen,

I require your assistance. Until last weekend I had a PERFECTLY running 1992 300E 4MATIC. I lost all my power steering fluid and when I brought to my mechanic I told him to change the pump since I had a spare which he did.

After, he noticed that it was not the pump, but a hose that had a leak and said that he would no longer do what I say without verifying the problem himself.

I drove home form the garage, about 4 miles and I had lost my power steering again and now my 4matic warning light was on and therefore not working. I returned to the garage and he could not find a leak anywhere’s. He refilled the power steering and let it run till the air bubbles dissipated and took it out for a test drive, about 3 miles, 4matic was working again and power steering was fine as was the fluid level.

I took the car for a 20 mile drive on the highway and when I got back to the house the 4matic warning light was on and no power steering. I went back to the garage, the power steering fluid was basically gone and we could not find any leak.

Does anyone have a suggestion? I tend to think it is air in the system causing the problem. What is the relationship between the power steering pump and the 4matic? The hydraulic fluid level increased in the reservoir.

Thank you for your assistance.

The pump is a tandem pump. Basically two pumps in one. If the fluid level increased in the resevoir, that is where the powersteering fluid is going.
The pump you installed is bad, or the return lines may have possibly been crossed. Resealling these pumps is pretty difficult to say the least. I would reinstall the old pump.

replaced the power steering and all is OK, 4matic intermittent figure I have to bleed the system or drain and replace since some p/s fluid gone into the hydraulic reservoir