Here's a general outline of the process. Specific steps and torque specifications will vary depending on the engine (likely a 3.8L V6, but could be a different engine). You MUST consult a repair manual specific to your vehicle's year, make, model, and engine size. A Haynes or Chilton manual is a good investment.
1. Preparation:
* Safety First: Disconnect the negative battery terminal. Wear safety glasses and gloves. Work in a well-ventilated area.
* Gather Tools: You'll need a variety of tools including wrenches (metric), sockets, ratchets, screwdrivers (Phillips and flathead), pliers, a drain pan, coolant recovery container, new coolant, new water pump gasket, and possibly a new thermostat and thermostat gasket (good preventative maintenance to do while you're in there).
* Consult Repair Manual: This is crucial. The manual will have specific instructions, torque specifications, and diagrams unique to your vehicle.
* Cool the Engine: Let the engine cool completely before starting. Hot coolant will cause severe burns.
2. Drain the Coolant:
* Locate the drain plug on the engine block (usually low on the side of the engine).
* Place a drain pan under the drain plug.
* Carefully loosen and remove the drain plug, letting the coolant drain completely.
3. Access the Water Pump:
* This will vary greatly depending on your specific engine. Your repair manual will guide you through removing belts, pulleys, fan shrouds, and other components that obstruct access to the water pump. This often involves removing the serpentine belt and possibly the fan.
4. Remove the Old Water Pump:
* Once you have access, disconnect the water pump inlet and outlet hoses. Have a container ready to catch any remaining coolant.
* Depending on the design, you may need to remove bolts holding the water pump to the engine block.
* Carefully remove the old water pump and inspect the mounting surface for any damage.
5. Install the New Water Pump:
* Install the new water pump gasket according to the repair manual's instructions.
* Carefully install the new water pump, ensuring it is seated properly and the gasket is not damaged.
* Tighten the bolts to the torque specifications specified in your repair manual. Over-tightening can crack the water pump or engine block.
6. Reassemble:
* Reinstall all components you removed to access the water pump in reverse order of removal.
* Reinstall hoses and reconnect any electrical connectors.
* Refill the cooling system with the correct type and amount of coolant. Refer to your owner's manual.
* Bleed the cooling system to remove any air pockets. This is often done by running the engine and squeezing the upper radiator hose.
7. Check for Leaks:
* Run the engine for a few minutes and carefully check for any leaks around the water pump and hoses.
Again, I strongly emphasize that this is a simplified overview. You absolutely MUST use a repair manual specific to your 1989 Buick Park Avenue to complete this repair safely and correctly. Failing to do so could lead to engine damage, personal injury, and costly repairs. If you are not comfortable with this level of automotive repair, seeking professional help is strongly recommended.
