don't know what you are working on, but there is a silicon spray for belts its called a silicon belt dressing
LOW AIR PRESSURE IN YOUR TIRES loose accessory belts such as alternator can squeal
The belts are squealing because they are either loose or worn out.The belts are squealing because they are either loose or worn out.
Tighten the belts
check the belts
The belts are not aligned correctly, or something is bent; pulley, bracket, look and see . The belt should look straight.
The belts twist because the accessory pulleys are out of alignment.
Depending on how many miles are on your vehicle. If you have 35k or more you need to replace your serpentine belt or all of your accessory belts. And if you have 89k or more you need to replace your serpentine or accessory belts and your timing belt.
2 accessory belts and 1 timing belt.
There is one timing belt and three accessory belts.
Loose accessory belts (probably alternator or fan). These stop squealing when they get warm. You might need a new belt, or just tightening.
Check the belts. The most common cause of squealing is a worn or loose belt on the front of the engine.
If the belts are new and tight then one of the driven accessories is having bearing trouble, try to track it down by listening to where the noise is coming from and then with the belt off turn the pulley checking for resistance or side to side play.