Take the belt off, un-bolt the idler pulley, bolt the new pulley on, and finally put the belt back on and Viola!!
one
Are you talking about the "idler pulley"? They are quite simple to change. Loosen the serpentine belt by using a socket on the center of the tensioner pulley, slide the belt off the idler pulley, use a socket to pull the center bolt of the idler pulley and replace the pulley with a new one.
I assume you mean the idler pulley on your timing assembly, if this is the case then the belt is too tight loosen tensioner pulley. if you mean the automatic tensioner pulley for your alternator and A/C and the like, the you probably need a new tensioner] Good Luck
The idler pulley is attached by a 14mm hex head bolt. Although the pulley turns counter-clockwise, suggesting that the bolt might be left-handed threads, it is in fact right-handed. A 1/2" drive ratchet with a 14mm socket will loosen the bolt if turned in a counter-clockwise direction. Be sure and loosen the belt tensioner, located below the alternator, and loosen but not remove the other alternator bolts, prior to removing the idler pulley.
On the belt routing diagram under the hood (near the grille, but under the hood) you will find the location of the 'tensioner' pulley. You need to get a 15mm socket and place it on the bolt on the tensioner pulley. Then use a ratchet to put clockwise pressure on the bolt to loosen the tension on the belt. This will allow you to remove the belt from the idler pulley, remove the bolt, put on the new pulley. Now put clockwise pressure on the tensioner pulley again to put slack in the belt so you can slip it around the new idler pulley. You're done.
The starter of the 1994 GMC Sierra 1500 pickup is located on the dashboard. It is usually attached by a small wire.
Remove belt and check to see that it rotates freely and smoothly
Using a 15mm wrench, turn the bolt in the center of the idler pulley clockwise to relieve tension and remove the belt.
Get a socket and a ratchet. Find out what socket fits the nut on the idler pulley. The whole idler arm should rotate counterclockwise. That'll relieve belt tension so you can replace the belt.
In the fuel tank
behind the harmonic balancer