Disclaimer: This is general guidance. Incorrectly performing this repair could damage your engine. If you're unsure about any step, consult a qualified mechanic.
Tools You'll Need:
* Repair Manual: A Chilton's or Haynes manual specific to your 1990 Cadillac DeVille is essential. It will provide detailed diagrams and torque specifications.
* Jack and Jack Stands: Safely support the vehicle.
* Wheel Chocks: For added safety.
* Wrench Set: Metric and possibly SAE, depending on your specific car.
* Socket Set: Metric and possibly SAE, with extensions and a ratchet.
* Screwdrivers: Phillips and flathead.
* Pliers: Needle-nose and slip-joint.
* Drain Pan: To catch coolant.
* New Water Pump: Ensure you get the correct replacement part for your engine.
* New Thermostat (Recommended): While you're in there, replacing the thermostat is a good preventative measure.
* New Thermostat Housing Gasket (Recommended): To prevent leaks.
* New Water Pump Gasket: Comes with some water pumps, but check.
* Coolant: The correct type for your DeVille (check your owner's manual).
* Gloves: To protect your hands.
* Safety Glasses: To protect your eyes.
* Torque Wrench: Crucial for tightening bolts to the correct specifications.
Procedure (General Steps - Consult Your Repair Manual for Exact Details):
1. Safety First: Disconnect the negative battery terminal. Allow the engine to cool completely before starting.
2. Drain the Coolant: Locate the drain plug at the bottom of the radiator and carefully drain the coolant into your drain pan.
3. Remove Serpentine Belt: Consult your repair manual for the specific routing of your serpentine belt. You'll need to loosen the tensioner pulley to remove the belt.
4. Remove Accessory Components: This might include removing the fan, fan shroud, or other components that obstruct access to the water pump. Again, your repair manual is critical here.
5. Remove the Water Pump: This typically involves removing several bolts holding the water pump to the engine block. Note the position of any components you remove.
6. Replace the Water Pump Gasket: Clean the mating surfaces of the engine block and water pump thoroughly before installing the new gasket.
7. Install the New Water Pump: Carefully install the new water pump, ensuring it sits flush against the engine block.
8. Reinstall Components: Reassemble all components removed in reverse order, ensuring everything is properly seated and tightened to the correct torque specifications (consult your repair manual).
9. Reinstall the Serpentine Belt: Make sure the belt is routed correctly over all the pulleys.
10. Refill the Cooling System: Carefully refill the cooling system with the correct coolant mixture. Consult your owner's manual for the proper ratio of coolant to water.
11. Bleed the Air from the Cooling System: This is crucial to prevent overheating. There are usually bleeder screws on the engine block or radiator; consult your manual for their location and bleeding procedure.
12. Check for Leaks: Run the engine for a while and carefully check for any leaks around the water pump and other components.
13. Reconnect the Battery: Once everything is running smoothly and there are no leaks, reconnect the negative battery terminal.
Important Considerations:
* Torque Specifications: Using the correct torque is crucial to prevent damage to the engine block and water pump. Use a torque wrench and consult your repair manual for the correct values.
* Coolant Type: Use the correct type of coolant specified in your owner's manual. Using the wrong coolant can damage your engine.
* Repair Manual: This is not a substitute for a proper repair manual. The steps above are general; your specific DeVille might have variations.
This is a complex job. If you lack experience with auto repair, it's highly recommended that you take your vehicle to a qualified mechanic. Attempting this repair without the proper knowledge and tools could lead to further damage to your vehicle.
