Tools You'll Likely Need:
* New serpentine belt: Get the correct size and type. Your local auto parts store can help you find the right one if you provide your vehicle's VIN or engine details.
* Socket wrench set: Various sizes, including metric and possibly SAE.
* Wrench set: Possibly needed for some tensioners.
* Ratchet: For quicker tightening and loosening of bolts.
* Extension bars: To reach some hard-to-access bolts.
* Pliers or needle-nose pliers: Possibly needed for belt routing or removing old belt.
* Gloves: Protect your hands.
* Shop rag or paper towels: For cleaning.
* Jack and jack stands (recommended): For easier access and safety.
* Wheel chocks: For safety.
* Repair manual: Absolutely essential for detailed instructions and diagrams.
General Steps (Consult your repair manual for specifics):
1. Safety First: Park on a level surface, engage the parking brake, and chock the wheels. Disconnect the negative battery terminal. Consider using jack stands if you're working under the van.
2. Locate the Tensioner: The serpentine belt is kept under tension by a tensioner pulley. Identify this pulley; it will usually have a bolt or lever to release the tension. Your repair manual will show its location and how to access it.
3. Release Belt Tension: This is the crucial step and varies widely depending on the tensioner mechanism. Some have a bolt you loosen with a wrench, allowing you to rotate the tensioner pulley and release the belt. Others have a lever that you may need to pry or push with a tool. Refer to your repair manual for the *exact* procedure. Never force anything.
4. Remove the Old Belt: Once the tension is released, the belt should slip off the pulleys. If it's stubborn, use pliers to carefully work it off.
5. Install the New Belt: Carefully route the new belt onto the pulleys, following the same path as the old belt. Your repair manual will have a diagram showing the correct routing. Make sure the belt is properly seated on all pulleys.
6. Re-engage the Tensioner: After the belt is routed correctly, slowly re-engage the tensioner until the belt is taut.
7. Tighten the Tensioner Bolt (if applicable): If you loosened a bolt to release tension, tighten it securely to the manufacturer's specifications (found in your repair manual).
8. Reconnect the Battery: Reconnect the negative battery terminal.
9. Check for Proper Routing and Tension: Make sure the belt is properly seated on all pulleys. Try to twist the belt; it shouldn't be too loose or too tight.
10. Start the Engine: Briefly start the engine to ensure the belt is running smoothly and no squealing is present.
Important Considerations:
* Diagram: Use the diagram in your repair manual religiously. Misrouting the belt can cause serious damage to the engine.
* Tension: The belt needs the correct amount of tension. Too loose and it will slip; too tight and it will put undue stress on the components.
* Pulley Condition: Inspect the pulleys for cracks, damage, or excessive wear. Replace any damaged pulleys.
* Belt Wear: Regularly inspect your serpentine belt for cracks, fraying, or glazing. Replacing a worn belt prevents more costly repairs.
Again, this is a generalized guide. Always consult a repair manual specific to your 1991 Chevy G20 van and its engine. If you're not comfortable performing this repair yourself, take it to a qualified mechanic.
