Mitsubishi Repair: Slipping P/S & A/C belt, straight edges, mid point

Question
1996 TE Magna 2.4 (4 cyl.) auto.
I have replaced the P/S, A/C drive belt many times & cannot stop it slipping (squealing). How tight can I go without doing damage to the P/S & A/C bearings. I have also tried anti-slip belt spray.

Answer
Ron,
There are special tools you can get to measure the deflection of the belts.  But with a couple of straight edges, you can check it yourself.  At the mid point of any belt, you should be able to push down on it to between 1-2 inches.  If it's so tight that you cannot push down it at all, then it's too tight.  But you can keep adding tension to the belt to see if stops squealing without doing damage to the bearings.  If you are able to tighten it so much where there's no deflection, and it's still squealing, you may have a problem with the one or more of the pulleys.
Good luck!