Here's a general outline. This is not a substitute for a repair manual specific to your 1990 Cadillac Sedan Deville. Consult a repair manual for detailed diagrams, torque specifications, and any specific warnings or cautions for your model.
Tools You'll Need:
* New serpentine belt: Get the correct belt for your car. The size is usually printed on the old belt or can be found in a parts store catalog using your VIN.
* Wrench set: You'll likely need various sizes, including those to loosen the tensioner pulley(s).
* Socket set: Similar to the wrench set.
* Ratchet and extensions: To reach those hard-to-access bolts.
* Pliers: Possibly for some tasks.
* Gloves: To protect your hands.
* Jack and jack stands (highly recommended): To safely lift the car and provide access to the underside.
* Repair manual: Essential for precise instructions and torque specifications.
Steps (General):
1. Locate the Serpentine Belt: Identify the serpentine belt that runs around the various pulleys (alternator, power steering pump, water pump, etc.).
2. Identify the Tensioner: The tensioner is a pulley that allows you to loosen the belt's tension. It might be spring-loaded or require a bolt to be loosened. This is the most critical part. Your repair manual will show you exactly where it is and how to access it.
3. Loosen the Tensioner: Using the appropriate wrench or socket, carefully loosen the tensioner. This will release the tension on the serpentine belt. Be cautious! The tensioner might have a spring that could unexpectedly release. Sometimes you need to use a tool (like a belt tensioner tool) to hold the tensioner while you remove the old belt. Others you can carefully use a wrench, but again, consult your repair manual for the specific procedure for your vehicle.
4. Remove the Old Belt: Once the tension is released, carefully slip the old serpentine belt off the pulleys. Work your way around, one pulley at a time.
5. Install the New Belt: Route the new serpentine belt onto the pulleys in the same order as the old belt. Again, your repair manual is crucial for the correct routing. Getting this wrong can damage components.
6. Tighten the Tensioner: Once the new belt is on all pulleys, slowly tighten the tensioner bolt (or release the tensioner tool). Ensure the belt is properly seated on all pulleys.
7. Check Belt Tension: Make sure the belt is not too tight or too loose. A slightly loose belt will often squeal. Too tight and you can damage the pulleys, bearings, and the belt itself.
8. Double-Check Routing: One more time, visually inspect to ensure the belt is routed correctly around all pulleys.
9. Start the Engine: Start the engine and check for any squealing noises or unusual vibrations. If problems exist, immediately turn off the engine.
Important Considerations:
* Proper Tension: Incorrect tension is a common mistake. The repair manual will specify the correct tension.
* Belt Routing: Incorrect routing can lead to premature belt wear or damage to components.
* Safety: Work safely. Use jack stands, wear gloves, and don't put any body parts near moving parts.
* Repair Manual: Using a repair manual specific to your 1990 Cadillac Sedan Deville is highly recommended, even crucial.
This is a general guide. Without a repair manual specific to your vehicle, you risk damaging your car. If you are not comfortable performing this repair, take your car to a qualified mechanic. Replacing a serpentine belt incorrectly can lead to significant engine damage.
