I just wanted to thank those that posted tips on changing the serpentine belt on an S70, I did mine this morning and it only took me 15 minutes and no problems at all! As usual, the advice here was FAR more helpful than reading the Haynes manual (which doesn't even have a routing diagram).

I used the "home-made" tensioner tool suggested by bh82 - an 11mm crowsfoot attached to a socket extension. But since my socket extension wasn't very long I left the rachet on for even more leverage - worked great! The rachet was at a 90 degree angle and pointed towards the bacl of the car (away from the moment of force).

I also did the whole thing from the top, not through the wheel well as some people (and Haynes) have suggested. My small hands were able to fit down in there with no trouble.

Steps I followed:

1. Lifted coolant overflow bottle off it's bracket, unplugged the sensor from the bottom and lifted the bottle - still attached to hoses - up on top of the engine out of the way.

2. Took a small allen wrench and inserted the short end into the hole at the top of the tensioner

3. Pulled the tensioner forward using the crowsfoot - socket tool, held tensioner in place where the 2 holes line up at the top while with other hand I slid the allen wrench through the second hole to secure it. Released the tool and the allen wrench held the tensioner. Removed the tensioner tool.

4. To give myself more arm room, I unplugged a sensor or something near the A/C recharge port... in fact can anyone tell me what this is for? It has electrical tape on it, seemed a bit brittle, and I wonder if it's something critical I should check on (indicated by arrow):


5. Worked the old belt off (it was stiff and dry and had hairline cracks on the inside, probably not too bad but I feel better knowing it is new for the upcoming long drive.

6. Put on the new belt starting with the cam and A/C pullies at the bottom, then under the tensioner and up to top pully, leaving idler pully for the last.

7. Inserted the crowsfoot tensioner tool and pulled forwards a bit to slide the allan wrench out of the holes, gently released the tensioner. Checked belt on each pully and re-connected other unknown plug, coolant sensor and slid coolant bottle back onto bracket.

Done! Look at that shiney new belt.

Only tools needed: