* Incorrect Airbag Installation: This is the most common reason. The airbags need to be seated correctly within their mounts. Even a slight misalignment can cause a noticeable lean. Double-check the manufacturer's instructions and ensure they are fully and properly seated in the suspension. One might be twisted or not pushed all the way into place.
* Airbag Deflation/Leak: A new airbag could have a manufacturing defect or a small puncture that's causing it to slowly deflate. Check both bags for any visible damage or leaks. You might hear a hissing sound if there's a significant leak. Inspect the air lines and connections for cracks or loose fittings as well.
* Uneven Air Pressure: Even if the airbags are correctly installed, uneven air pressure between the left and right sides will cause a lean. Make sure both airbags are inflated to the manufacturer's recommended pressure. Use a quality pressure gauge to verify. Many newer vehicles have systems that automatically manage air pressure; if yours does, a fault in the system could be causing this.
* Suspension Component Issues (Pre-existing): The problem might not be the new airbags themselves. A worn-out or damaged spring, strut, or other suspension component on the high side could contribute to the lean, even with new airbags. If the lean was present *before* the airbag replacement, it's crucial to investigate these other parts.
* Incorrect Airbag Selection: Did you purchase the correct airbags for your specific year and model of Ford Expedition? Using the wrong parts is a guaranteed recipe for problems.
Troubleshooting Steps:
1. Visual Inspection: Carefully examine both airbags and their mounting points. Look for any obvious signs of damage, misalignment, or leaks.
2. Pressure Check: Use a pressure gauge to verify the air pressure in both airbags. They should be equal. Inflate them to the specified pressure if necessary. If your system automatically inflates, look for any error codes.
3. Recheck Installation: If possible, have someone assist you in carefully removing and reinstalling the airbags to ensure they are properly seated.
4. Check for Leaks: Spray soapy water around the airbags and air lines to check for leaks. Bubbles will indicate a leak.
5. Inspect Other Suspension Components: Have a qualified mechanic inspect your suspension for other potential problems if the lean persists after checking the above.
If you're not comfortable working on your suspension system, it's best to take your Ford Expedition to a qualified mechanic. Improperly installed or faulty airbags can lead to further damage and safety concerns.
