Tools and Materials Needed:
- New water pump
- Replacement coolant (Subaru Genuine Coolant or equivalent)
- Funnel
- Socket set
- Ratchet
- Pliers
- Screwdrivers
- Jacks and jack stands
- Drain pan
1. Prepare the Vehicle:
- Park your Subaru Impreza on a level surface and turn off the engine.
- Allow the engine to cool down.
- Engage the parking brake and chock the wheels.
- If necessary, raise the front of the vehicle with jack stands or use ramps.
2. Locate the Water Pump:
- Open the hood and remove the engine cover (if equipped).
- The water pump is usually located on the front or side of the engine block.
3. Drain the Coolant:
- Place a drain pan underneath the radiator or water pump to catch the old coolant.
- Open the radiator drain plug or the water pump drain plug (depending on your model) to drain the coolant.
4. Disconnect the Water Pump Hoses:
- Locate the hoses connected to the water pump and use a pair of pliers to remove the hose clamps.
- Disconnect the hoses carefully, allowing the remaining coolant to drain into the drain pan.
5. Unbolt the Water Pump:
- Locate the bolts holding the water pump in place.
- Use the socket set and ratchet to loosen and remove the bolts.
6. Remove the Old Water Pump:
- Once all the bolts are removed, carefully remove the old water pump from the engine block.
- Be careful not to spill any remaining coolant.
7. Clean the Mounting Surface:
- Clean the mounting surface of the engine block where the new water pump will be installed.
- Remove any old gasket material and ensure the surface is clean and free of debris.
8. Install the New Water Pump:
- Place the new water pump in position and align it with the mounting holes.
- Install the bolts and tighten them securely in a criss-cross pattern to distribute the force evenly.
9. Reattach the Water Pump Hoses:
- Reattach the water pump hoses to the respective connections.
- Secure them with hose clamps.
10. Refill the Coolant:
- Remove the radiator cap and use a funnel to pour in the new coolant.
- Refill the coolant until it reaches the “FULL” mark on the coolant reservoir or radiator.
11. Bleed the Cooling System:
- With the engine off, start the bleeding process by squeezing the radiator hoses to release any trapped air.
- Start the engine and let it run for a few minutes.
- Continue squeezing the hoses until the engine reaches its operating temperature and the thermostat opens.
- Monitor the coolant level and top it off as needed.
12. Test the System:
- Close the radiator cap and take the vehicle for a short test drive.
- Monitor the temperature gauge to ensure the engine is not overheating.
- Check for any leaks around the water pump and hose connections.
13. Replace the Engine Cover:
- Once you are satisfied that the water pump is functioning properly and there are no leaks, reinstall the engine cover (if equipped).
Remember, if you are not comfortable performing this task, it's best to take your vehicle to a qualified mechanic.
