Draining/flushing pentosin

[timofej.crift at att.net]

> IIRC, you are supposed to replace the pentosin in your car 
> every two years. Since my car is 4 years old, I figure it's time.

The pink stuff is "lifetime" according to Audi.  That means I change mine whenever I do the timing belt.  It has held up well and I have seen no corrosion on my internal cooling bits on both my 99 A9 or 95 90Q when I recently did the timing belt service. The Pentosin blue on the other hand needs to be changed every two years.

Cheers,

Tim