Tools You'll Need:
* New wiper arms: Make sure you purchase the correct ones for your 2004 Impala.
* Socket wrench: Likely a 19mm or possibly a 13mm, but check your owner's manual or online for the specific size. This is for removing the wiper arm nut.
* Penetrating oil (like PB Blaster): This helps loosen any rusted or stuck nuts. Apply this *before* attempting to remove the nut. Let it sit for 10-15 minutes to work its magic.
* Gloves: Protect your hands.
* Rag or shop towels: To clean up any spilled oil or debris.
* Flathead screwdriver (optional): In some cases, a small flathead can help gently pry the wiper arm if it's stubborn. Use caution to avoid scratching the windshield.
Steps:
1. Park and Turn Off the Vehicle: Park your Impala on a level surface, turn off the ignition, and engage the parking brake.
2. Disconnect the Battery (Recommended): While not strictly necessary, disconnecting the negative (-) battery terminal is a safety precaution to prevent accidental short circuits.
3. Prepare the Wiper Arms: Lift the wiper arms away from the windshield.
4. Apply Penetrating Oil: Spray penetrating oil onto the nut that secures each wiper arm to the wiper arm spindle. Allow it to sit for 10-15 minutes to work.
5. Locate and Remove the Nut: Locate the nut securing each wiper arm to the spindle. Use your socket wrench to carefully remove the nut. Sometimes, the nut is difficult to reach; you may need an extension on your socket wrench.
6. Remove the Wiper Arm: Once the nut is removed, the wiper arm should be relatively easy to pull off. However, they can sometimes get stuck. If it's stubborn, use gentle, even pressure to pull straight up. If necessary, use the flathead screwdriver *carefully* to help pry it loose. Avoid scratching the windshield.
7. Install the New Wiper Arms: Align the new wiper arm with the spindle and push it firmly onto the spindle. Screw the nut back on and tighten it securely. Do not overtighten.
8. Repeat: Repeat steps 5-7 for the other wiper arm.
9. Reconnect the Battery (If Removed): Reconnect the negative (-) battery terminal.
10. Test the Wipers: Turn on your wipers to ensure they are functioning correctly.
Important Considerations:
* Windshield Damage: Be extremely careful to avoid scratching the windshield. Work slowly and methodically.
* Nut Size: Double-check the correct socket size before attempting to remove the nuts.
* Stubborn Arms: If the wiper arms are extremely difficult to remove, consider seeking professional help to avoid damage.
This guide provides general instructions. Specific details may vary slightly depending on the exact model and year of your 2004 Chevrolet Impala. It's always advisable to consult your owner's manual or an online repair manual specific to your vehicle for the most accurate and detailed instructions. Pictures or videos for this specific repair on your car model are also very helpful to find online.
