ACE Filter.

Does any one know at what interval should the ACE fluid and filter be changed at as my disco is 7 years old and 112k mileage and there is no mention of it ever being done in the service history. I ask because the orange warning light comes on after a long motorway journey but if i stop and restart it stays off till the next long run either the next day or several weeks later. I was wondering if possibly the fluid is getting too hot and thin and triggering a pressure sensor or is there another known fault with them. Is the fluid easy enough to change and will it self bleed or need diagnostics to do it? Cheers guys.:blabla:

According to Rave the filter should be changed at 72,000 miles but there is also lots of "Caution" type advice relating to ACE so unless you know what you are doing I'd be very careful messing about with it. As far as I could see Rave doesn't tell you how to bleed it but it does refer to using Testbook.