Car Fix DIY Videos

http://chevroletforum.com/how-tos is the leading Chevy Silverado resource for technical DIY guides. Replacing the A/C belt tensioner in your Silverado is easy and can be completed in the comfort of your driveway. For the full step-by-step article, please visit http://chevroletforum.com/how-tos/a/chevrolet-silverado-1999-2006-how-to-replace-a-c-belt-tensioner-392577

The Vortec 4.8, 5.3, and 6.0 liter engines have a main accessory drive belt for the water pump, power steering, and alternator. The air conditioning compressor is driven by a separate belt that is mounted low on the engine and behind the accessory belt.

Both belts have GM auto-tensioners, which maintain spring pressure to automatically adjust for optimum tension as the belt wears. Belt noise begins when the spring weakens or the pulley bearing begins to wobble.

In this comprehensive guide, you will learn how to replace the A/C belt tensioner in your Silverado.

This easy job takes about an hour and costs around $100 dollars. A professional will likely charge double that amount.

This job requires a replacement A/C belt tensioner, an 8 millimeter socket wrench or battery side terminal wrench, 15 millimeter and ⅜ inch drive socket wrench, a flathead screwdriver, electrical tape, and maintenance ramps or jack stands if necessary.

Step One – Disconnect the battery

Make sure the engine is cold before beginning work.

Use an 8 millimeter wrench or battery side-terminal wrench to disconnect the negative terminal from the battery. To prevent inadvertent contact, push the negative cable away from the battery and place electrical tape over the negative battery terminal.

Step Two – Remove the intake duct

Use a flathead screwdriver (or 8 millimeter wrench) to loosen the hose clamps at the mass airflow sensor fitting and intake manifold fitting.
Slide the intake duct off the fittings.
Lift the intake duct slightly, and use a flat head screwdriver to pry the intake duct bracket off of the clip attached to the upper radiator hose.

Step Three – Remove the accessory drive belt

Place a 15 millimeter socket wrench on the center bolt head of the tensioner pulley. You can use an extendable wrench for extra leverage.
Rotate the tensioner clockwise against the spring, and hold it. Then slip the belt off the tensioner pulley.
Release the tensioner slowly back to the spring stop.
Slip the belt off the crank pulley and let it hang.

Step Four – Remove the splash pan

Use a 15 millimeter socket wrench to remove the five bolts holding up the splash pan.
Remove the splash pan and set it aside.

Step Five – Remove the A/C belt and tensioner

Insert a ⅜ inch drive wrench into the square hole of the tensioner.
Rotate the tensioner clockwise against the spring, and hold it. Then slip the belt off.
Release the tensioner slowly back to the spring stop.
Remove the two 15 millimeter bolts and then remove the tensioner.

Pro Tip
Examine the belt for cracked ribs or fraying, and consider replacing it.

Step Six – Install the new A/C tensioner and belt

The most common A/C tensioner across the GMT800 line is the GM number 12580196.

Replacement bolts are GM number 11515767. Make sure to verify with your VIN when ordering.

Position the new A/C tensioner and tighten the bolts.
Fit the A/C belt around the A/C compressor pulley and the inner track of the crank pulley.

Rotate the tensioner and slip the belt over the tensioner pulley.

Step Seven – Re-install the splash pan and accessory drive belt

Position the splash pan and tighten the five 15 millimeter bolts.

Fit the belt around the outer track of the crank pulley and around the other pulleys. Refer to the belt routing diagram on the radiator shroud.
Rotate the tensioner for enough slack to finish and fit the last portion under the smooth idler pulley.

Step Eight – Re-install the intake duct and reconnect the battery

Connect the intake duct bracket to the clip on the upper radiator hose.Slide the duct over the mass airflow sensor as well as the intake manifold fittings, and tighten the clamps.

Remove the electrical tape from the negative battery terminal, and reconnect the negative lead.