Its happened to all of us. We go out in the morning and start up the Forester and the horrific screeching and squealing of the accessory belts fills the air, wakes the neighbors, and annoys the wife beyond anything you could do yourself. But don't worry, you have a man card. You got it when you changed your oil a few weeks ago. If you can do that surly you can quiet a measly belt right? Sure you can, and I am here to help you.
I took pictures of my 2004 XS but it should apply to almost all Forester motors.
First lets gather round all the tools me might be using:
10mm deep well socket optional
12mm deep well socket optional
3" or 6" socket extension
12mm stubby wrench optional but will make things easier
12mm offset wrench optional but will make your life MUCH easier
wd-40 or pb blaster optional
rubber gloves optional
magnetic tray optional (for holding nuts and bolts and sockets)
belt dressing optional
(I couldn't find my offset 12mm wrench so I made a custom "shallow well" socket)
Now that you have all the tools ready, its time to get dirty.
Start with a cool engine. Pop the hood and lets see what we got...
There are (3) bolts and (1) nut holding on the (2) covers that you need to remove.
To get the first cover off, remove the nut on the right side of the cover, then remove the bolt on the left side.
To remove the second cover, remove the bolt on the left. Then loosen the bolt on the right (on the side of the alternator). Its a long bolt that goes clear to the back side of the alternator.
Its hard to see, but there is a nut in there...
If you do remove the bolt entirely this metal bracket will fall down into an abyss, it will take you 20 minutes to find it, and another 30 to get it out from said abyss. Here is a picture of the culprit...
As you can see the guard has a slot so you can slide it out without removing the long bolt.
Now that you have a naked engine, its time to get to work.
Adjusting the power steering belt. This is pretty straight forward. Loosen the bottom bolt (the lock bolt). Now tighten the top bolt (the adjusting bolt) until the belt is snug. I do not know the proper way of telling how a belt is snug, I just feel it. I will come back and edit this post with the proper info on this.
Once the belt is tightened correctly, re-tighten the lock bolt and check that the belt is still the proper tightness.
Now that belt is done, so its on to the AC belt.
Loosen the bottom lock nut. Tighten the belt using the adjusting bolt, and re-tighten the lock nut. This is where thing are a little tight and using the stubby wrench and offset wrench came in very handy. Tighten everything back up and double check the belt tension.
Now that everything is in proper adjustment, lets double nay triple check ourselves again. Check torque on all the bolts you have loosened and check the belts tension one last time. Now start the car and let the belts run for a minute or two. Spray the belt dressing on them following the manufacture's directions.
Re-assembly. Its time to put everything back the way you found it. Its just the reverse of how you took it apart. Just make sure you torque everything down properly (again I went by feel for the guards, its not a huge deal. Just check the torque on the alternator bolt)
Once everything is back together you can put your tools away and clean up. You just earned another man point.
here are some Subaru papers showing this. Print them out for reference if you would like.