Well,

as i change my coolant myself roughly every two years or about 50k miles, i have just changed my original t-stat,sensor and tubing at a 170k milestone and 8 years not bad then.

For info cc i just normally lift the car on the right side, take the coolant expansion task top off, undo the drain plug and let it run out and then flush it though with clean water. I always use distilled water for both the flush and the top up, 50/50 volvo recommend.

Run your engine once you have done the change and re-top up as necessary.

mark in leeds/uk.
uk voc 94 850glt 2l 20v 172k.