Here's a general guide. This is NOT a substitute for a repair manual specific to your vehicle's year and engine. Consult a repair manual for precise diagrams, torque specifications, and any unique steps for your specific LeSabre engine (3.1L, 3.8L, or possibly a different one).
Tools You'll Need:
* New serpentine belt: Get the correct size and type from an auto parts store (provide your VIN for accuracy).
* Wrench set: You'll need various sizes, likely including metric.
* Socket set: Again, likely metric, and possibly including both standard and deep sockets.
* Ratchet: A good quality ratchet will make the job much easier.
* Wrench or socket for tensioner: This is crucial. The tensioner is usually a pulley that needs to be loosened to release the belt's tension. Your repair manual will show you which tool is needed – it's often a special tool or a long wrench.
* Gloves: To protect your hands.
* Jack and jack stands (highly recommended): This makes accessing the belt much easier and safer. Never work under a car supported only by a jack.
* Repair manual: Specific to your 1999 Buick LeSabre and engine type. This is invaluable.
Steps (General Outline – Refer to Your Repair Manual):
1. Safety First: Disconnect the negative battery terminal.
2. Access: Jack up the front of the car and securely support it with jack stands. Locate the serpentine belt.
3. Locate Tensioner: Identify the tensioner pulley. Your repair manual will show you its location and how to release tension. This is usually the hardest part.
4. Release Tension: Using the appropriate wrench or socket, carefully loosen the tensioner. This will allow you to remove the belt. Be aware the tensioner may spring back forcefully when released; be prepared and keep your hands clear.
5. Remove Belt: Once the tension is released, carefully work the belt off the various pulleys.
6. Install New Belt: Route the new belt onto the pulleys in the same order as the old one (use the old belt as a guide if needed). Ensure it's seated correctly on all pulleys.
7. Re-tension: Tighten the tensioner pulley to the specifications in your repair manual.
8. Check Tension: Make sure the belt is properly tensioned. You should be able to slightly twist it about 90 degrees between two pulleys. Too tight is bad, and too loose is equally bad.
9. Reconnect Battery: Reconnect the negative battery terminal.
10. Test: Start the engine and check for any squealing or slipping. Check the belt for proper alignment and tension.
Important Considerations:
* Tensioner: The tensioner is a critical component. If it's seized or damaged, you'll need to replace it.
* Pulley Alignment: Make sure all pulleys are properly aligned; misalignment can cause premature belt wear.
* Belt Routing: The routing of the belt is crucial. Get this wrong and you could damage components. Your repair manual will have a diagram.
* Torque Specifications: Always follow the torque specifications in your repair manual when tightening the tensioner. Over-tightening can damage the tensioner or pulleys.
This is a general guide. Always consult a repair manual specific to your 1999 Buick LeSabre's engine before attempting this repair. If you are uncomfortable performing this task yourself, take it to a qualified mechanic. Improperly replacing the serpentine belt can lead to serious engine damage.
