My 2007 XC90 has been a wonderful car thus far, and I have put just about 115,000 miles on it over the years. I was flipping through my maintenance manual the other day and saw that I had missed the 112,500-mile replacement period for the serpentine belt. So, I grabbed my tools and headed to the garage expecting the worst, but to my surprise, the belt-replacement process was actually just like nearly every other belt I have done in a car.
The tensioner pulley on my 2007 XC90 was between the crankshaft pulley and the alternator on the belt-routing path. To relive the tension on the belt, I placed a breaker bar and socket on the bolt in the center of the tensioner pulley assembly, and rotated the breaker bar clockwise.