Peterbilt 389 Glider Air Springs & Level Valves

Frequently Asked Questions About Peterbilt 389 Glider Air Springs & Level Valves

What do air springs and level valves do on my Peterbilt 389 glider?

Air springs support the weight of the cab or suspension and absorb road vibration, providing a smoother ride and reducing stress on the frame. Level valves work alongside the air springs to automatically adjust air pressure, keeping the cab or axle riding at the correct height as load and road conditions change. Together, these components help maintain ride quality, stability, and proper alignment.

How do I know if my air spring or level valve needs to be replaced?

Common signs include a sagging or uneven cab height, excessive bouncing or harsh ride quality, visible cracks or bulges in the air spring bellows, air leaks (often heard as a hissing sound), or the compressor running more frequently than normal. If the cab sits noticeably lower on one side or doesn't return to normal height after hitting a bump, the level valve linkage or valve itself may need attention.

Will these air springs and level valves fit my specific Peterbilt 389 glider build?

Fitment can vary depending on the model year, cab suspension configuration, and whether your glider was built with a specific OEM setup. We recommend checking the part number against your truck's existing components or referencing your build sheet before ordering. If you're unsure, our team can help confirm compatibility based on your VIN or existing part numbers.

Can I install a replacement air spring or level valve myself, or should I have a professional do it?

Many experienced owner-operators and shop technicians replace air springs and level valves themselves, as the process typically involves disconnecting air lines, removing mounting hardware, and swapping the component. However, proper adjustment of the level valve linkage is critical for correct ride height, so if you're not familiar with this process, having a qualified technician handle the installation and calibration is a good idea to avoid ride height or handling issues.

What's the difference between OEM and aftermarket air springs and level valves, and does it matter which I choose?

OEM parts are built to match the exact specifications of your original equipment, which can simplify fitment and performance matching. Aftermarket parts are often made to equivalent standards and can be a cost-effective alternative, but quality can vary between manufacturers. We carry trusted brands and can help you choose an option that balances fit, durability, and budget for your specific application.