[urq] Red or Green?

[spot.ontheroad]

No it's not a political debate, it's the question of what kind of fluid should be used in the power steering/brake assist system on a 1987 WR quattro.

Here's the picture: 1987 WR quattro, with worn out rack. PO ran it on Red ATF. I followed suit and ran it with Red ATF (Dexron 111). A friend very kindly donated a temporary rack that enabled me to get the original reconditioned. The newly reconditioned rack is recieved back with a label attached to it stating that the warranty will be invalidated if anything other than Mineral based Green VAG G002000 spec fluid is used.
I ask Audi about this. They confirm that Green is correct and only green should be used but are unable to advise whether Green can be mixed with the residue of the red. I contact the manufacturer of the Green stuff who say it IS OK to mix Green with the remains of the red but suggest flushing with green first. OK so I am all set to refill with Green when I read the (I acknowledge these are now v.old) Audi IST documents which state (page 44) that "the hydraulic assist system is operated with ATF Hydraulic oil". Now I don't know what to re-fill it with. I don't know who to believe. I have read on-line that Red ATF is three times more viscous than the Green and has a detrimental effect on the life of seals etc. Puts undue strain in them and will lead to leaks. (I certainly had a leaky rack)
Can anyone point me in the direction of something definitive on the subject that states:
a)whether the Green Mineral Based oil can be used to replace the Red ATF  without having to replace any seals or other components
b) which oil is correct for the car ( it has the original tall metal reservoir if that helps any)
c)what the effects of running the Red instead of the Green are?  
As usual, any help on this will be gratefully received. I am anxious to get it al back together ASAP as it is my daily driver and using my old 1963 Daimler to get around is gradually forcing up the world Oil price with it's heavy consumption.

Many thanks

Keith

'87 WR

incidentally, I can confirm that the only difference between the rack of a coupe quattro and a ur-q is the pipework attached to it - and the part number of course. They ARE interchangeable.BTDT