If you take the belt off you can them remove the pulley by taking the bolt out of the center. If the bolt does not come out turn it the other way because some are left hand threads

Then put your finger in the hole in the bearing and spin the pulley. If it feels rough at all replace it because it will fail possibly locking up and ruining the belt.

If it spins smoothly it should be ok.

However on the ones that have black rubber covering the gap between the center of the bearing and the out side of the bearing you can grease them if you want. You need a very small flat blade screwdriver. Sometimes it helps to use 2 screwdrivers to ease the seal out using 1 screwdriver to keep the seal from slipping back into the grove while you continue prying the seal out with the other screwdriver.

Clean all of the dirt off the bearing first. At the outer edge of the black rubber you can carefully pry out the seal working it just a little at a time until it comes out. You can then grease the bearing. You don't need to fill the area more than about 1/2 way. Then start the seal back in the outer grove in the bearing and carefully press the seal back in the grove using a circular motion going around the bearing. There is very thin metal under the rubber so try not to bend it or it will not seal properly. If you do bend it you can try to straigten it.

Some seals pry right out and some are harder to get out. After you have done a couple it gets pretty easy.

 

i have replaced the tension pulley and the idle pulley and the a/c pulley, my blazer has never stopped squealing i swear it from the alternator or the water pump now.. althought i thought the same with all the other pulleys so far.. iam beginning to come to the conclusion its in my head the fact that it cant be found.. any other ideas?

 

while the belts are squealing, spray them with water. If they stop then you need to replace the Belts.

 

Spraying with water sometimes stops the squealing but sometimes the squealing gets worse. It can't hurt to try. If the squealing stops temporarily it confirms that the noise is coming from the belt. This can be caused by a glazed or worn belt or a bad tensioner. But it also can be from a misaligned pulley. You may need to have the alignment checked. take a look at this link.

Dayco: Dayco Releases New Belt Diagnostic Kit

 

Look at the tensioner while the engine is running. It should be pretty solid in one place with just a little movement. If its bouncing pretty rapidly, then the tensioner is bad.

 

If its the tensioner, don't buy one from auto zone, they suck! and will go bad in a yr. Try Napa.

 

I finally fixed this problem on mine today, it was another poster in this forum that suggested pulling the power steering pump pulley out by 1/8 of an inch. I honestly couldn't think of why this would work because the noise seemed to be coming from the top idler pulley but it worked. No more noise! I wish I had tried this before I replaced all three pulleys, the belt (twice) and rebuilt the alternator with new bearings.