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Discussion Starter #1
I always hear about flushing brake fluid every two years but never anything about PS fluid. I noticed yesterday when the outside temperature was 10 degrees that there was a whine from the PS pump until the car warmed up. This is the first time I noticed this. Is PS fluid hygroscopic such that it should be changed out just like brake fluid? If so does the same interval apply?
 

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manual talks about checking the level and topping up if need be, but not doing a change..... there is a dipstick on the back of the reservior cap... and the manual says only ATF can be used and a trained tech should top up... maybe you don't just pour it in...
 

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i have changed mine
 

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In Finland pretty popular "update" to many cars is to change Redline power steering fluids to replace old original ones, and usually it makes an good improvement to the power steering.

And my fluids looks like they are burned somehow and these are only 2 years old - I guess it can't be bad to change once in a while...
 

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Discussion Starter #6 (Edited)
Thanks. I'm finding differing opinions on the internet (surprise). The majority seem to support changing it because of debris that can gather over time. It does appear it is not hydroscopic.

For those that have changed their PS fluid, where did you drain it from or did you use something to suck it out? One article says to drain it at the PS pump.

Found these articles.

http://www.partsamerica.com/Maintenance/MaintenancePowerSteeringFluid.aspx

http://www.waynesgarage.com/articles/misctips.htm

http://www.startribune.com/cars/11355646.html
 

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Actually they designed the hoses to fail before the fluid- so you'll wind up replacing the fluid anyway when you replace the leaking PS hose!

:)

A
 

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Anyone familiar with the exact procedure if someone, in fact, does want to completely drain the power steering fluid and fill with a fresh synthetic fluid? Because in the past all I have done is drain the resevoir with a turkey baster and fill with fresh fluid and let it mix with the old fluid. Continuing this procedure until it looks as though the fluid coloring is getting close to the color of the fresh fluid that is being added.

I feel as though this would waste a lot of fluid and it would in turn contaminate the new fluid that is being added. Any thoughts?
 

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Another turkey baster person

I too have used the turkey baster procedure. I'll be interested in hearing what other folks have to say about this.
 

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PS fluid should be changed every few years. Most people don't bother. Any ATF, regular or synthetic, will work in the BMW systems. Of course, any respectable M owner will only use synthetic oils...

Normal method for changing fluid on any PS system is to suck as much fluid out of the resivoir as you can, add fresh fluid. Repeat this a few times and you will have gotten majority of the fluid changed.
PS system is kinda like an auto tranny in that you will never get all the fluid out, so you cant really do a 'true' oil change.
You can also crack the return hose fitting (after throughly cleaning around the fitting, of course!) at the pump and let whatever will drain out to drain. This just increases the amount of fluid you drain out at a time.
 

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The procedure I used on another car:

Disconnect the return line into the reservoir, point it into a drain pan, then plug off the hole in the reservoir (short piece of hose with a bolt shoved in it works well)

Fill the reservoir with fluid, have someone start the car, and turn the wheels back and forth while you pour fresh fluid into the reservoir. It will empty FAST.

When the fluid comes out clean in the drain pan, shut the car off, hook the return line back up, top off the fluid.

As an alternative, you can use a cheap ATF for the initial flush (1 gallon jug), then switch to a better fluid like Mobil1, couple quarts should do it.
 

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I got mine flushed when I had two of the hoses replaced... why not?
 

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Discussion Starter #13
I still plan to try to replace my fluid, but short term I found my problem; it's just low. It's at the very bottom of the dipstick. My owners manual says nothing at all about PS fluid. It mentions every other fluid in the car. I assume the OEM stuff is not synthetic, correct?

Also, the dipstick has two marks on it. I assume the top one is the max fill line?
 

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+1 !

My power steering hose started leaking so I had my indy mechanic replace the hoses and also flush the powersteering fluid system.

Actually they designed the hoses to fail before the fluid- so you'll wind up replacing the fluid anyway when you replace the leaking PS hose!

:)

A
 

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Also, the dipstick has two marks on it. I assume the top one is the max fill line?
I don't think so. The PS uses ATF, like others mentioned. ATF expands a lot when it gets warm, so I think the bottom line is full mark cold and the top is full mark hot. You want to leave at least some air space at the top for thermal expansion, or KABOOM.

Flushing using the disconnect the return hose seems like a good idea. Just don't make a mess.

As for type of fluid, I'm sure any Dexron II ATF will do, but if you're going to do this, you may as well put in a good brand like Mobil 1, Redline or Royal Purple.

If there is noise afterwards, it's likely b/c of air in the line. To bleed a power steering line, you just rack it from one side to opposite lock on the other a few times and that will purge all the bubbles out.
 

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Low Fluid...What is it ?

Is the power steering reservoir on the drivers side next to what I guess to be the oil filter housing ? I just noticed that mine is low on the dip stick..no data in the manual. ATF marked on top. Any suggestions as what to fill it with? My wife's Honda uses special power steering fluid and we we told to use nothing else. Seems kinda strange, especially given all of the oil discussioin and formulations.

Thanks !!
 

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Is the power steering reservoir on the drivers side next to what I guess to be the oil filter housing ? I just noticed that mine is low on the dip stick..no data in the manual. ATF marked on top. Any suggestions as what to fill it with? My wife's Honda uses special power steering fluid and we we told to use nothing else. Seems kinda strange, especially given all of the oil discussioin and formulations.

Thanks !!
ATF = Automatic Transmission Fluid. And that is what you should fill it up with.

d-
 

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I know it proberly more expensive but if your are not sure what to use just go to a BMW garage and get their atf fluid.
 

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Is the power steering reservoir on the drivers side next to what I guess to be the oil filter housing ? I just noticed that mine is low on the dip stick..no data in the manual. ATF marked on top. Any suggestions as what to fill it with? My wife's Honda uses special power steering fluid and we we told to use nothing else. Seems kinda strange, especially given all of the oil discussioin and formulations.

Thanks !!
When I replaced one of the hoses, I got a "free" system flush:1:, so I chose to renew with synthetic. I believe our cars did not come with synthetic.

I use Mobil 1 ATF.

Remember, the dipstick has a "hot" and "cold" mark, so read the proper one.
Regards,
Jerry
 
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