Tools You'll Need:
* New serpentine belt: Make sure you get the correct size and type for your Astro. The parts store can help with this, providing your engine size and year.
* Wrench(es): You'll likely need various sizes to loosen and tighten the tensioner. Check your manual for specifics.
* Socket wrench and sockets: Useful for accessing some bolts, especially if the tensioner is bolt-based.
* Pliers or a belt tensioner tool: A tensioner tool makes the job much easier, but pliers *might* work depending on the tensioner design.
* Gloves: Protect your hands.
* Jack and jack stands (optional but recommended): This will give you better access to the bottom of the engine. Always properly secure the vehicle before working underneath.
Steps:
1. Safety First: Park your Astro on a level surface, engage the parking brake, and chock the wheels. Disconnect the negative battery terminal to prevent accidental shorts.
2. Locate the Belt and Tensioner: The serpentine belt runs around various pulleys (alternator, power steering pump, water pump, etc.). Identify the belt tensioner. It's a pulley mechanism with a means of applying tension (usually a spring-loaded arm or a bolt).
3. Loosen the Tensioner: This is the crucial step. *Consult your repair manual for the correct procedure*. Some tensioners are loosened by turning a bolt, while others might have a lever or require specialized tools. The goal is to create enough slack to remove the old belt. Be careful; the tensioner is under spring pressure, and it can spring back quickly.
4. Remove the Old Belt: Once you've loosened the tensioner, carefully slip the old belt off the pulleys. Start with the smallest pulley, working your way around.
5. Install the New Belt: Carefully route the new belt around the pulleys in the *same* direction as the old belt. Pay close attention to the routing; a misrouted belt can cause serious damage. Again, your repair manual is your friend here.
6. Release Tensioner (Carefully!): Slowly release the tensioner, allowing the belt to seat properly on all the pulleys.
7. Check Belt Alignment: Ensure the belt is properly seated on all the pulleys and there's no rubbing or misalignment.
8. Tighten Tensioner (If Applicable): If you loosened a bolt on the tensioner, tighten it back to the manufacturer's specified torque.
9. Reconnect Battery: Reconnect the negative battery terminal.
10. Test: Start the engine and check for any squealing or unusual noises. Check the belt for proper tension by pressing on it midway between two pulleys. It should only deflect slightly.
Important Considerations:
* Repair Manual: Get a repair manual for your specific year and engine. It'll have diagrams showing the belt routing and tensioner location.
* Tensioner Type: Tensioner designs vary. Some are spring-loaded, some are hydraulic, and some use a bolt for adjustment.
* Broken Parts: While replacing the belt, inspect the pulleys and tensioner for wear or damage. If you see cracks, excessive wear, or signs of failure, you should replace those parts as well.
If you're uncomfortable with this repair, it's best to take your Astro to a qualified mechanic. Improperly installing the belt can damage your engine components.
