Tools You'll Need:
* Socket wrench and sockets: The size will depend on your specific pulley bolt. It's likely a large bolt requiring a significant amount of torque.
* Wrench: Possibly a box-end or open-end wrench to hold the pump itself stationary while you loosen the pulley bolt. A proper holding tool is ideal (see below).
* Pulley puller: A three-jaw puller is generally recommended for this type of job. Failing to use a puller may damage the pump or pulley.
* Penetrating oil (like PB Blaster): Apply liberally to the pulley bolt several hours, or even overnight, before attempting removal to break any corrosion.
* Ratchet extension(s): May be needed for better leverage depending on your access.
* Gloves and safety glasses: Always protect yourself.
* Optional but highly recommended: Power Steering Pump Holding Tool: This tool fits onto the pump's shaft and prevents it from rotating while you remove the pulley bolt.
Procedure:
1. Safety First: Disconnect the negative battery cable to prevent accidental shorts.
2. Prepare the Area: Work on a clean, well-lit surface.
3. Penetrating Oil: Generously apply penetrating oil to the pulley bolt. Let it soak for several hours or even overnight. Reapply as needed.
4. Access: You'll need to access the pulley bolt. This may require removing other components (e.g., serpentine belt, possibly the alternator depending on your access). Consult your repair manual for the correct procedure to remove the serpentine belt.
5. Hold the Pump: Use a wrench to firmly hold the power steering pump body from turning while you loosen the pulley bolt. A dedicated pump holding tool is strongly preferred as it prevents damage to the pump.
6. Loosen the Pulley Bolt: Use the appropriate socket and ratchet to loosen the bolt. It will likely be very tight, so be prepared to use significant force. A breaker bar may be necessary. Turn counter-clockwise.
7. Remove the Pulley Bolt: Once the bolt is loose, remove it completely.
8. Use the Pulley Puller: Carefully install the three-jaw pulley puller according to the manufacturer's instructions. Gradually apply pressure to remove the pulley. Avoid using excessive force, which could damage the pump or pulley.
9. Inspect: Inspect the pulley and power steering pump for any damage. Replace if necessary.
10. Reassembly: Reverse the steps for reassembly. Ensure the pulley is properly seated and the bolt is tightened to the manufacturer's specified torque. Again, consult your repair manual.
Important Considerations:
* Torque Specifications: Follow the torque specifications found in your repair manual. Over-tightening can damage the pump or pulley, while under-tightening can cause it to come loose.
* Damaged Pulley or Pump: If the pulley or pump is damaged during removal, replace it immediately.
* Serpentine Belt Routing: If you removed the serpentine belt, ensure you replace it correctly. Incorrect routing can cause damage to the belt and other components.
This is a general procedure; specific details may vary depending on your vehicle's configuration. Always refer to a repair manual specific to your 1991 Mercury Sable 3.8L for precise instructions, torque specifications, and diagrams. If you are not comfortable performing this repair yourself, it is best to take your vehicle to a qualified mechanic.
