My method of replacing the fluid must work as it comes out clear every time I replace it (and the same colour too), after 14 years no issues. This was the same method that I used on my Discovery 2 which had ACE as well. The price of the genuine Landrover filters is stupid money these days. I bought a bulk supply of genuine Landrover filters for only AU$65 each.

Agree, you cannot do it stationary without the requisite tool that plugs into the valve block and manually opens the valve. I have tried to see if connecting a 12v supply to the valves causes them to do something, but no joy on the front (I bought a spare block and wiring loom to try to figure this one out)!

Also worth noting that even when stationary, there us fluid being pumped around what I understand to be the front half of the system, as if you leave it a few minutes then touch the 4 pipes in the front wheel well, 2 of them will be warm…..

…. I never got to the bottom of my ACE woes on my previous L320, nor could I find a single person in Kent that was prepared to work on it, so I eventually lost patience and fixed it by purchasing a replacement L320