Is it ok to replace CHF 7.1 with synthetic trans fluid

[The Bigfella]

What's this about all the $$$$? Cost me about $20 for a tin. Beats running any sort of risk.

[genphreak]

What's this about all the $$$$? Cost me about $20 for a tin. Beats running any sort of risk.

Where i Oz can I get it tho BigFella? BMW, Merc, OMG!

No doubt it needs to be flushed in this car. A tin for $20- whereabouts should I try?

Thanks for the concern everyone, especially Erich- I know the cause/effect paranoia is high on bimmer forums but farout why o why ever use anything other than ATF in such as system... esp when the same model comes with the same stuff and does!

Oh, of course- how silly of me. So you can put in different seals.

I always knew BMW were just playin' with us...

[shogun]

try the others which have the same stuff, maybe you can get it there easier:

Pentosin CHF 11S Synthetic Hydraulic Fluid

Pentosin CHF 11S Synthetic Hydraulic Fluid - Fully synthetic hydraulic fluid for steering and central hydraulic systems. This synthetic fluid is correct for many later models which specify synthetic fluid. Temperature range -40C to +130C. Should not be mixed with ATF fluids or other power steering fluids. ***Note - this is currently sold as part # G00200 by Audi/VW as of 1990, replacing Pentosin CHF7.1 The CHF11S is correct for Audi/VW 1990 and later models, while Audi/VW 1989 and earlier models can use either 7.1 or 11S although 11S is recommended. Audi/VW states that 7.1 and 11S can be mixed if necessary but we suggest draining and flushing the system if you are changing from 7.1 to 11S***

1 liter can. Equivalent to the following: VW/Aud# G002000, BMW# 81.22.9.407.758 and 82.11.1.468.041, Porsche# 000.043.203.33, Rolls-Royce & Bentley# RH5000

15.16

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Pentosin CHF 7.1 Hydraulic Fluid

Pentosin CHF 7.1 Hydraulic Fluid - Special mineral based hydraulic fluid for use in power steering, central hydraulic and suspension level control systems. Should not be mixed with ATF or other fluids. Temperature range -40C to +100C. ***Note - this was sold as part # G00200 by Audi/VW through 1989. As of 1990 Audi/VW is selling Pentosin CHF11S as their part # G002000. 1989 and earlier models can use either although the 11S is recommended. Audi/VW states that 7.1 and 11S can be mixed if necessary but we suggest draining and flushing the system if you are changing from 7.1 to 11S***

liter can. BMW# 81.22.9.407.549, was also *formerly* VW/Audi #G002000

11.30

from:
http://www.germanautoparts.com/chemi...luids/Pentosin
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The biggest difference is the double vane pump instead of a single pump, and of course the seals (maybe).
I have just disassembled a double vane power steering pump and renewed all gaskets and seals. Not that difficult.

[Morgenster]

And here an old design from IceTea from Netherlands on Readfly how he tried to find out the best way to get all the wrong stuff out his car
http://img337.imageshack.us/img337/7...aulicsyki4.jpg

Well, I'm getting scared, but the link doesn't work properly, so any other ways to see that method?

[Ross]

The moral of the srory here folks is to repair any leaks so the cost of the fluid is moot once there is no need to continually top it off.
$20 is a bite for a liter of oil but cheap insurance against the cost of overhauling the hydraulic system.

[shogun]

Well, I'm getting scared, but the link doesn't work properly, so any other ways to see that method?

I have it on another server also
http://s71.photobucket.com/albums/i1...mSchematic.jpg

[ryan roopnarine]

ok, this is getting annoying. if my car had chf 7.1 in it originally, i might feel different. also, i have to agree with ross--if you fix your leaks, the cost is moot. that having been said....


nothing posted here indicates that atf will f' up will mess up a non lad 7.1 system. the pentosin document says theirself that the issue is with putting 7.1 into 11 and vice versa. miscible is a very specific chemistry term. it does not mean that the fluid will destroy anything, it just means that the 11 and 7 will not combine, most likely the 11 will float on top of the 7.1 and appear to look like a different "phase". it is quite telling that pentosin would tell people that it isn't ok to mix the two fluids, but it is ok in a pinch, and that it is ok to do so if you completely flush the system--but that mixing them produces "floucculent". it is hydraulic fluid, it is going to get into everything, but a cursory flush makes it ok? chf stands for central hydraulic fluid, mineral (for 7.1). atf is a hydraulic fluid. pentosin isn't going to be the group to ask for the suitability of mixing the two, zaharand-fabriken (sp?) is, but nobody has bothered to ask them in any of this. i wouldn't ask valvoline if their transmission fluid is suitable first, i'd ask the vehicle manufacturer/transmission manufacturer first. i've had atf in my 7.1 capped vehicle for in excess of 100k miles and the only issue that has resulted is a dead spot on center that has more to do with the age of the vehicle than of the fluid running through the system.

[Ross]

I am cautious from experience. An Audi(that called for 7.1)I once owned had been filled with ATF. Perhaps coincidence but I had to overhaul the pump and the rack. The seals for the pump were made of special material, I noticed that much. I'll let you guys figure out what that cost.
I haven't a clue about the chemistry of these fluids but have a firm grasp of the labor and expense involved to fix an ailing system.

[Morgenster]

ok, this is getting annoying. if my car had chf 7.1 in it originally, i might feel different. also, i have to agree with ross--if you fix your leaks, the cost is moot. that having been said....


nothing posted here indicates that atf will f' up will mess up a non lad 7.1 system. the pentosin document says theirself that the issue is with putting 7.1 into 11 and vice versa. miscible is a very specific chemistry term. it does not mean that the fluid will destroy anything, it just means that the 11 and 7 will not combine, most likely the 11 will float on top of the 7.1 and appear to look like a different "phase". it is quite telling that pentosin would tell people that it isn't ok to mix the two fluids, but it is ok in a pinch, and that it is ok to do so if you completely flush the system--but that mixing them produces "floucculent". it is hydraulic fluid, it is going to get into everything, but a cursory flush makes it ok? chf stands for central hydraulic fluid, mineral (for 7.1). atf is a hydraulic fluid. pentosin isn't going to be the group to ask for the suitability of mixing the two, zaharand-fabriken (sp?) is, but nobody has bothered to ask them in any of this. i wouldn't ask valvoline if their transmission fluid is suitable first, i'd ask the vehicle manufacturer/transmission manufacturer first. i've had atf in my 7.1 capped vehicle for in excess of 100k miles and the only issue that has resulted is a dead spot on center that has more to do with the age of the vehicle than of the fluid running through the system.

I'm going to ask ZF then.

[shogun]

That is not only ZF. ZF just produces the power steering pump and the steering gear.
There is a regulating valve in the engine room, there is a regulating valve at the rear axle, there are 2 shocks, there are 2 "bombs", and if you have a E32 750, there is also the brake booster unit which is also using the same fluid. And there are pipes and hoses connecting the single parts.
Ever checked the price of a regulating valve for LAD? No repair parts available. Ever checked the price of the regulating valve inside the engine room?

The only one which can tell you something for the whole system, is BMW. And for that, have a look into the owners manual.
No need to ask ZF in my opinion.

If you ever have opened a steering gear which is hydraulically supported by this fluid, and see all these tiny little channels etc., (I have done 2 within the last 3 weeks) you would be very relucatant to make any experiment with such a system.
If it fails, it will costs you $$$$