Power Steering Flush Fluid?
 

Do I need to use power steering fluid to flush the system? Can I just use some cheap atf or motor oil? Is flushing even really necessary? Where can I get the seal for the cap?

You just replace the power steering fluid. Larrybible has a good post on the technique.
Be sure to replace the filter. It is in the bottom of the resevoir.

I used atf at the beginning, you go through the stuff fast, end with ps fluid.

Definitely not motor oil.

I use cheap NAPA PS fluid - buy a couple of gallons on sale for about 7 or 8 bucks. Works great.

alright, I got two quarts of the cheapest atf I could find and used a quart that was sitting in the garage. Red stuff. Followed the wikka article, it wasn't clear whether or not I was supposed to hear these awful noises while doing it. Anybody else? It also didn't drain it all, so when I put in the new clear ps fluid, it mixed with the red atf, it came up with this pink nonsense. When I was flushing, the stuff came out really frothy too. The only thing that seemed to go well was the filter replacement.

86 560SEL

i tried to do a flush.. had wife in the car.. but couldn't keep enough fluid in the reservoir to even get a chance to try to turn the wheels. as soon as she started car, the fluid disappeared and i could barely pour it in fast enough to keep the reservoir from going dry. had her turn car off after just a few seconds. ran through two quarts in hardly any time.

so changed the filter and filled reservoir with fresh ps fluid.. original stuff was red, obviously ATF. as the car has only 76K miles, probably original stuff. so now have mixture of PS fluid and ATF. and it's still red colored.

Same problem
 

I had the same problem with my '96 E300D (W210, OM606NA). I used most of a gallon of inexpensive NAPA PS fluid. For the next change, I'm considering two possibilities

(1) put a clamp on the return hose so the fluid doesn't drain so fast; I should then be able to keep the reservoir full but am concerned about the pressure building up to dangerous levels.

(2) remove the belt and turn the pump by hand; that may require taking the weight off of the front wheels so the steering wheel can be turned without power assist.

Jeremy

Rotating the engine with the starter (intermittently if necessary) might be a third possibility to consider. Best done with the front end elevated.

at the dealer, we just pulled out the filter and sucked the reservoir dry. didn't get the old fluid out of the whole system, but if you do that every 15k, your fluid will be clean enough. unless its really dirty, then you might want to try flushing it.

That's why I laugh when I hear people say "only the dealer works on my car."

I tried spinning the pump with a drill motor and a belt made from vacuum tubing made into a loop. It did not work, perhaps the pump was not turning fast enough to build up the necessary pressure. Consequently, I doubt that cranking the engine would work, either. Ended up with wife as assistant and had the usual problems keeping the reservoir full but the job eventually got done.

JEBalles,

I had red/brown stuff in my 85.

I bought a gallon of PS fluid cheap at NAPA. I cleaned out a 5 gallon VO container really well and let it fully dry. I put the PS fluid in that.

Then, as a catchment I routed the return hose down underneath the car into another VO 5 gallon container.

The idea is to be able to pour PS fluid super fast from the cubie - you cant pour fast enough off the little quart jugs to keep up with the pump. And the 5 gallon catch bucket is nice insurance against spills.

If the mix you have now is pink do it again so you have one type of fluid only in there. Its worth the effort, you'll never have to flush it like this again.

dd

Cant the steering box be drained , say with the front wheels off the ground, pump cover off and move the steering side to side? Seems this would leave the system pretty clean if left to drain for a couple hours. ... I haven't done this, just asking;)

Steering box drain?
 

I do not know whether the steering box has a drain. In any case, it would leave the system full of air that would have to be bled out. I do not know if this would be a serious problem, just want to add it as a concern.