re: Mixing 7.1 and 11s pentosin, and flushing out my mistake

[Phil Rose <pjrose@servtech.com>]

Jim,
I know the label says never mix any other kind of fluid with the synthetic
11S. However, my understanding is that Audi dealers have been doing that
(mixing) ever since Audi switched over to using the 11S (which is the one
and _only_ flavor of Pentosin they have dispensed for years now under the
alias of G002 000). Maybe they've been destroying hydraulic components by
doing that, but I kinda doubt it.

Having said that, I do have some concern about whether or not an apparent
absence of ill effects from adding 11S to the older (7.1) systems
guarantees that it's OK to go in the _other_ direction (i.e., adding 7.1 to
an 11S system).

I personally wouldn't worry about adding as little as 1/3 liter of 7.1 to a
system containing 11S, and wouldn't bother with flushing 'till the new
high-pressure hose is put in. At that point, you could do a flush to set
your mind at ease about compatibility and also to freshen up the fluid,
which might be pretty dirty anyway.

Phil R.

>Date: Mon, 28 Dec 1998 20:06:04 -0800
>From: "James A. Desveaux" <desveaux@ucla.edu>
>Subject: Mixing 7.1 and 11s pentosin, and flushing out my mistake
>
>Thanks to Peter, Phil, and others regarding fluid leaks around the bomb on
>my car.  Today I discoverd a major leak from the front part of the high
>pressure hose connecting the hydraulic pump and the rack.  Both the pump and
>rack appear fine.  Before I tested for leaks, I topped up the reservoir with
>about 1/4 to 1/3 of a can of Pentosin 7.1--the old stuff.  I called
>Europarts for the hose (not cheap) and a can or so of Pentosin.  He reminded
>me that '90 and later Audis are supposed to use the synthetic pentosin, and
>it's a bozo no-no to mix them.  Later today I found out at one of the
>moreless local Audi dealers that they ONLY stock one pentosin.  Of course,
>they could give no more particulars than that.  I looked at the plastic
>container and, sure enough, it's 11s.  My car, '91 200QW had the hydraulic
>pump replaced in June '97 at Graham Automotive, the Audi dealer in Sioux
>Falls, SD.  I called them a while back and they gave me the impressive that
>they'd put 7.1 in it, but they didn't say that.  They said they used the
>same stuff they've been using.
>
>I suspect I've now mixed two types of Pentosin, and will need to purge the
>system.


Phil Rose				Rochester, NY
'91 200q				mailto:pjrose@servtech.com
'89 100