Originally Posted by
onehundred80
The original colour was blue, flush it out and add Zerex it shows up as greenish yellow. Some of the old coolant gets hidden away and mixes with the Zerex.
Clean does not count for much, it’s the qualities that count and they diminish with age just like us.
Thanks so much for this guidance! I will indeed do the swap to Zerex in the next few weeks. I think this car deserves "undiminished" quality, and I'm happy to provide it. Cheers.