one of the pullies that doesn't drive anything will have a bolt head in the center, turn this counterclockwise, and as you do so, the tesion will be removed. as soon as you let tension of the socket however, the tension will be re-instated.
On the main drive serpentine belt, there is a tensioner pulle. it is positioned at 6:00. relieve tension remove belt. reverse process for reinstallation.
Serpentine puller
I believe it to be on the fan belt mechanisim..the pulley that allows you to adjust the tension.
put a wrench on the tensioner pully and pull it to release tension on the belt
After you have released the tension from the belt, remove the 2 obvious bolts that hold it to the engine block.
It provides the proper tension on the serpentine belt so as it is not too tight or too loose.
What did unhook or break while you were under the hood ?
You need a 1/2" ratchet or a Johnson bar. The idler pulley has a square 1/2" hole that the square on the ratchet will fit in and allow you to turn the pulley and relieve the tension.
To relieve serpentine belt tension you need to use a Rachet arm or Breaker bar, the longer the better. (Many parts stores, such as Auto Zone will let you use their special tool made just for this purpose.) Fit the 3/8 square drive tip into a hole in the bracket which is attached to the Tension pulley. Once you insert the drive tip into the matching hole, simply turn the ratchet or breaker bar until the pulley rotates and releases the tension.
Using a 15mm wrench, turn the bolt in the center of the idler pulley clockwise to relieve tension and remove the belt.
Relieve the tension by putting a wrench on the tensioner and then remove the belt. www.trailvoy.com all the answers for your Trailblazer from true enthusiasts!
The tension on a serpentine belt is automatically set by the Idler Tension Pulley. If you find it is not correctly setting the tension, the the spring may be broken.