Greetings Benz Meisters. Thanks up front for all the great help on this forum. My problem is the steering gets hard, as if the power steering system is giving up, above ~1800 RPMs with the car stopped. Below 1800 it is fine. I don't really know how long it has been like this. I just happened to catch it in the parking lot today. On the highway it seems OK but I can't really turn the wheel enough to know. Can't see any leaks. I changed the fluid a few months ago. Used forum recommended MB fluid. Fluid level is on the low side but OK according to the lines on the little dip stick. This isn,t a show stopper, but I think something is not right. I would like to fix it before it becomes permanent. Hope someone can help.

Thanks, Dan

Just out of curiosity, why do you have the engine running over 1800 rpms with the car stopped? Is the system normal while driving?

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

Just trying to see if the engine RPMs affected the power steering.
It's too difficult to do with the car moving. My Indy is looking into it to see if he can figure it out. Any help here would be appreciated.

Dan

I need to bump this post because things are getting worse! Steering assist from power steering system is coming and going. Most noticeable at low speeds, like turning out of a driveway. I bought power steering fluid from Phil at Fastlane and changed the power steering fluid about 2 months ago. I can't see any leaks at the pump or the steering rack. There are no unusual noises and the fluid level is good. I think I have a problem with the pump or the rack but I don't know how to tell which one is the culprit (or something else?). Please, any advice on how to troubleshoot this so I can determine what is causing this. It would be very annoying to replace the pump only to discover the rack was the problem (&vice-versa!). Thanks for any help. This forum is great!

Dan

I had a "groaning" sound on my 1998 C230. This is a typical symptom of low fluid. I checked the fluid both cold and hot and it was well within the marks. I had the dealer "top it off" resulting that the fluid level ended up being "technically" a hair above the max line, basically when cold the level is at the min line for the hot range if that makes any sense. These marks are pretty small and close together so it is not an exact science. Anyway, long story longer, you might try putting in a little more of the very special magic secret German fluid that no one knows what it is but you have to use it ONLY. Also, there is a filter in that PS pump somewhere. That might be the problem. I am no expert on PS though. Just telling you my experience. Hope that helps.

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Maybe Gilly or MBDOC could shed some insight here.

The PS pump for my 97 C230 groans as well, and I was told at my last service that it was just low on fluid. I had already checked the fluid and it was fine, and after they suppoedly topped it off, it still groans. Bad pump?

I really know nothing about this subject, but, out of curiosity, does anyone know what actually "powers" the power steering pump? Is it a belt, electrical...?

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Michael

1988 300 SL (5 Speed)
1994 E320 Wagon
1997 C230

Belt. I have heard of new systems using electrical PS especially as it relates to the new 48V systems we will supposedly see some day, but I am unaware of any that have this yet. If anyone has any info on this I am interested to hear it. I imagine once electrical PS is implemented it will be "direct drive" and their will be no more pump and fluid which will be a good thing I think. All cars currently have belt driven pumps as far as I know.

My fluid level needed to be a little high, as I mentioned, to stop groaning. Does your groan all the time or just when you turn?

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

To clarify things, there are no unusual noises anywhere. Only symptom is occasional failure of power assist to actually power assist the steering. Fluid is topped and fresh. This has the plastic reservoir which I believe does not have a serviceable filter. Is that right? Assuming the pump or the rack is giving up, but how do I determine which one is the problem?

Dan

Not sure about MB because I haven't had to do any power steering repairs, but in most American cars it is necessary to "Bleed " the air in the system by turning the wheel all the way to the side and back and all the way to the other side while the car is running. Doing it several times is recommended to purge the air. Go all the way to each steering stop.

Tim

Fast lane shows PS filters for this car for just under $4.00. The price is right but how do you put it in? I don't know. And might not be you problem anyway. The air purge trick might be worth a try. Hopefully someone has some definitive advice for you.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

I did the wheel side-to-side maneuver when I changed the fluid. Couldn't hurt to do it again. I'll give it a try this weekend. Any help on how to determine if the pump or the rack could be the problem?

Thanks, Dan

Most likely it's the PS pump. Make sure there isn't any excess slack in the belt (over 15mm). Check the flange that holds the pulley and v-belt. I have seen PS flanges strip from the shaft and not affect the belt tension but the pulley skips on the shaft as it rotates.

Thanks. I'll check those tomorrow. One other clue to consider: With the engine at idle RPM there is no problem turning the wheel stop-to-stop. Only when the RPMs get up maybe 1500 or more does the problem happen.

Dan