do NOT mix Pentosin CHF 7.1 and 11S

[shogun]

And also do not replace one by the other.
Some people from the German 7-Forum and also now from the E34 Forum in German had contacted Pentosin. One got the reply by email, the other one talked with a head of a labority there.

To make the story short:

1. Where Pentosin CHF 7.1 is mentioned on the sticker of the reservoir, only refill CHF 7.1.

2. A mixing with other hydraulic oils could cause that additives could separat as a flocculent , which then could block valves etc. The instruction not to mix it is mentioned on the cans of the Pentosin 7.1
That is apparently also mentioned in a special internal BMW info for the repair shops.

3. CHF 7.1 contains special lubricants/additives, which are required by the older systems on E32 and E34
CHF 11S does not contain these additives in the required volume, it therefore cannot be used as alternative or replacement for 7.1 in case of topping up and/or replacement of Pentosin 7.1.

4 CHF 7.1 is green; CHF 11 is also green, but the colour is a slightly lighter green.

Here a copy of the email received in Germany from Pentosin:

Guten Tag Herr xxxxxxx,

vielen Dank für Ihre Anfrage, beide von Ihnen genannten Hydrauliköle CHF 7.1 und CHF 11 S dürfen nicht vermischt werden, da es zu Unverträglichkeiten von Einsatzkomponenten bei Vermischungen kommen kann, was wiederum im schlimmsten Fall zu Ausfall des Hydrauliksystems führen kann.
Dies gilt für Nachfüllungen, wie für Neufüllungen.

Wir hoffen Ihnen hiermit weitergeholfen zu haben und verbleiben

Mit freundlichen Grüßen
Deutsche Pentosin-Werke GmbH.

[Ross]

Had the dubious pleasure once of resealing a hyd. pump and replacing the rack on an Audi for that reason. PO thought castrol too expensive I guess.

[Spasso]

I am still pondering the dilemma of the red ATF in BOTH of my 530's. So far no noticeable problems but it looks like a power flush for both systems are in order. I have 4 liters of CHS 11s on hand for the job.

Both cars have the large reservoir, no dipstick and the cap says CHS11s. Both cars have ASC but neither have self leveling. They both run the single vane power steering pump.

Has anyone devised a way to clear the systems thoroughly without having to go to the Stealer?

I have a hand pump with hoses I use for filling transmissions etc.............but where to hook to the system to flush out everything with minimal loss of new Pentosin, 18.50 a liter!!

[Ross]

Buy a couple extra cans and do it twice.No leaks?

[shogun]

Read this one, someone from the U.K. contacted Pentosin:

Well I emailed Pentosin and here is their reply. It looks like I will have to think about flushing my power steering system:

--------------------

Dear Mr. Becker,

we can't confirm the statement of BMW.

Don't mix CHF7.1! Neither with LHM nor with CHF11S.

On the can is a text about the mixability of hydraulic fluids. I don't know where BMW got the information.

In case of questions or comments, please feel free to contact us.
______________________________

mit freundlichem Gruß / kind regards

Jan Möller

Deutsche Pentosin-Werke GmbH

phone : +49 4103 9134 10
fax : +49 4103 9134 71

mailto:j.moeller@pentosin.com
http://www.pentosin.com