[V8] Pentosin crisis

[Scott Justusson]

A lot of debate on this over the years, I personally find pretty amusing to reread, again...  The real issue is not the Audi Hydraulic Power Steering system mix of 11s and 7,1, but to the other uses of 7.1 and 11S.  Specifically, the 'non mix' warnings refers to power tops, shock oils, and suspension systems....  Where the small variations in viscocity indecies can cause 'possible' issue if components are sporting mixed fluids.  THIS CONCERN DOES NOT APPLY TO G002000-A2 specification in the Audi power steering system.  Hence the reason Audi issued TSB 48-89-T07 issued November 89 that clearly states they are 'mix' compatable in 7.1 PS systems.  Exactly the reason for no part number change on the top of the PS fluid resevoir, they are *equivalent" in every way to the proper operation and maintenance of Audi PS systems.  

 The idea that the seals go with synthetic is BS, or hoses goes with synthetic is also BS.  Because Audi used the same seals in the PS systems, hoses and seals for many years beyond the swap from 7.1 to 11S.
To compare specs:
7.1
http://www.pentosin.net/pressreleases/CRP-116_Pentosin_CHF7-1_V2.pdf
11S
http://www.pentosin.net/pressreleases/CRP-116_Pentosin_CHF11S_V3.pdf

If you were to look specifically on what will break down the hydraulic oil, the flash point is probably the best place to start.  Here 11S will operate in temps higher than the 7.1 without vaporization/cavitation.  Interesting to note (to you ATF users) Porsche Factory switched to 11S from ATF (no hardware changes) for better low temp and high temp Viscosity properties in TSB 9606
http://www.pcarworkshop.com/images/f/fe/PowerSteering_OIL_1996_640696.pdf

If you really want to improve your hydraulic system performance on your Audi, put an aux cooler for the PS fluid.  I've done this to a couple Audis, and find the fluid life is much longer, and I suspect the seal/hose life is too.  That said, Hydraulic immersed rubber deteriorates over time, which is exactly why you can find a good hydraulic hose shop in just about every small town USA.  The boys that work tractors and hydraulic construction/farm equipment see failures of rubber lines all the time.  

IIRC2 7.1 was discontinued in 2007, and any remaining stock (and there is a LOT) is available in the aftermarket.  To 11S, that is available in several flavors, including from Audi/vw/BMW/Mercedes/Porsche.  However, worthy to note 11S is now due to be phased out in favor of CHF 202 (backwards compatable - Audi G004000)  considered a Long Life Hydraulic Mineral oil.

I don't believe a mix of any of these CHF fluids in the power steering systems is a problem, as all the performance numbers are well within age tolerance numbers of the other offerings.  Want to be careful, pull the return line off the resevoir, and drain out the 'old' fluid...  There's 5 minutes!  That said, putting in 7.1 seems pretty absurd, given how quickly the Germans moved away from it starting in 1990.

HTH and my .02

Scott J
92 v8 11S






 

 

 

-----Original Message-----
From: Acadian Lion <Acadianlion at hotmail.com>
To: cobram <cobram at juno.com>
Cc: V8 <V8 at audifans.com>
Sent: Mon, Mar 18, 2013 5:08 pm
Subject: Re: [V8] Pentosin crisis


I’m going to check with the NAPA store here in town and see what it will really 
cost to have them order some in. They told me they CAN get it, and I would like 
to see if that is still true.  IF not, perhaps you wouldn’t mind calling the 
NAPA store there to see what they might sell some of their old stock for...if 
they in fact have any.  

My preference is to keep in the car what it has always had and I intend to do 
this until I can take the car to the shop and have the system drained completely 
and refilled.  That will likely be in May but not until.

Roger

From: cobram at juno.com 
Sent: Monday, March 18, 2013 5:37 PM
To: Acadianlion at hotmail.com 
Cc: V8 at audifans.com 
Subject: Re: [V8] Pentosin crisis

Audi also says that the transmission must be replaced as a complete unit.  11S 
is backward compatible, Napa bought all the 7.1 in bulk when Audi cleared it's 
shelves more than 10 years ago, there are  a few bottles on the shelf at the 
local Napa, and they look like they've been around longer than the store.  Mobil 
1 synthetic transmission fluid is compatible, several people are using it with 
no problems.  I haven't put a drop of Pentosin brand anything in any of my 
Audi's or other Teutonic beasts in decades because of the ridiculous price and 
the fact that the substitutes work just as well.  Mobil changed the DTE 
designation, these have all been used with no detrimental effects by other V8Q 
owners, Chevron and a few others are missing from the list because I have never 
seen those here in the North East.  

Copied from a previous post on the subject:

Atlantic ISO 10, 32, 46, 68, 100
BP Bartran 10, 32,Â* 46, 68, 100
Caltex Rando HD 10, 22, 32, 46, 68, 100
Castrol Hyspin AWS 10, 32, 46, 68, 100
Mobil DTE 24, 25, 26, 27
Shell Tellus 10, 32, 46, 68, 100
Valvoline Ultramax All Fleet 10W 10, 32, 46, 68, 100
Ampol Tecoma 10, 32, 46, 68, 100

What's the new Gold Infused steering fluid the dealer peddles going for now, $25 
a quart?  Not surprised they're not stocking any fluid for the type 44's 
anymore, as they are more than 10 years old.  I would trust the couple hundred 
V8Q and type 44 owners with decades of actual experience more as much as any 
tech who might have seen or worked on 2 or 3 V8Q's in his entire career.  Might 
be the greatest tech in the world, but you know what you work on regularly, and 
there's no tech out there anymore who regularly works on V8Q's.  11S and 7,1 are 
completely compatible, Audi dealers have only been allowed to restock with 11S 
since it came out, and it uses the same part number as in the Audi Bulletin I 
quoted. 

If it's a religious thing, let me know and I will be happy to check and see if 
the local Napa still has the 7.1 on the shelf, if they do I can pick up a couple 
quarts for you.  No idea of what they're asking for it, probably around $20 a 
can.

BCNU,
Experience is the name everyone gives to their mistakes.



On Mon, 18 Mar 2013 16:52:25 -0400 Acadian Lion <Acadianlion at hotmail.com> 
writes:
  Well, all this information is very interesting in that it is so diverse.  
Standing in the Audi dealer last Friday, I read the label on the current Audi 
power steering fluid (which is all they stock), and it specifically states on 
the container that it is NOT to be used with CHF 7.1.  They stock no 11S nor 
does anyone else I have spoken to from Belfast to Bangor, Maine.  VIP and NAPA 
can order 7.1 and VIP will eventually stock 11S once the changeover to O’Reilly 
Auto Parts is complete, which is a couple of month.

  The reason I search for 7.1 is because that is what is in my car, which was 
built in mid 1989 as a 1990 model. It is also the fluid the Audi dealer that I 
do have some trust for, used and was strict in their instructions. The service 
manager at that time was the service manager in that store when my car was sold 
new, so I had a certain level of trust.  Also, the mechanic in that Audi store, 
who was the ONLY Audi dealer tech to have touched my car was trained by Audi at 
the time of the V8 rollout.  (Yes, their gray hair was grayer than mine!). I 
have NEVER seen 11S on any of the autoparts shelves I have looked for here, 
although I have seen 7.1 in VIP and sometime ago, I seem to remember seeing it 
in NAPA. We have few other autoparts outlets.

  Roger