E32 Power Steering Fluid

86 911 · 86 911's Garage

We have a 1994 740i, and we are looking to add some power steering fluid. We picked up some"Prestone" power steering fluid at Kragen the other day and I want to know is this fluid is okay for the power steering system in the 740i? Does BMW require a special power steering fluid?

Thanks.

Bear · 06-17-2005, 06:08 PM

Maybe, but you need to check your owners manual as some used Pentosin 7.1, others Pentosin 11.0, and still others Dexron III. Do not top off without looking at the onwers manual.

Bear · 06-17-2005, 06:12 PM

I believe your car uses PENTOSIN 11.0 so do not use a substitute.

86 911 · 86 911's Garage

Thank you for giving me the PS brand. I'll go ahead and follow your advice.

86 911 · 86 911's Garage

I have another question regarding the PS fluid. My dad called the shop which services the BMW (they also put fluid in a few months ago) and asked what they put in as PS fluid. Thier answer was: "Transmission fluid". My dad asked why, and they said that transmission fluid works as PS fluid. Is this true? The man that we took the car to service it to was a German car mechanic. Can transmission fluid really be used in the PS system? Should I drain the fluid that he originally put in?

Thanks!

Bear · 06-21-2005, 03:16 PM

What Herman the German is saying is that he put Automatic Transmission Fluid (ATF) probably DEXRON III, in the PS reservoir. Unfortunately your car does not use ATF in the PS system, I am almost certain it uses PENTOSIN 11s (call a BMW dealer to be sure or check the owners manual or the decal on the PS steering reservoir if there is a decal). If I am corect you need to take a turkey baster and remove the fluid from the PS reservoir and then fill with the correct fluid. Too many independent mechanics are not familiar with the BMW and its' fluid system. For example (does not apply to your car), my 1988 750il had a LAD (auto leveling system) and the power steering pump used PENTOSIN 7.1 to run the PS, the brake booster (no vacuum system) and the self leveling system and woe be the owner that went to a shop for service with the shop with technicians that did not know the BMW and its' peculiarities. I have a married daughter with a 1994 BMW 530 and it also uses PENTOSIN 11s for the PS system.

Sorry for the long post, but I do not wish you to have issues down the road because the ATF in the PS system deteriorated the seals in the PS system.

86 911 · 86 911's Garage

Wow, thank you for the response. Yes, the car does take Pentosin 11S. Now, what would be the best way to drain and flush the PS system?

Thanks!

Bear · 06-21-2005, 06:06 PM

Here is what we Bimmer folk do: Take a turkey baster (really) and suck all of the fluid out of the PS fluid reservoir, and then refill with PENTOSIN. This will get most of the ATF out and you will be good to go (not enough ATF left to hurt and you will be diluting it with PENTOSIN. Glad I saw your question and was able to respond, this fluid issue is a common mistake in the BMW community.