Peterbilt 389 Air Springs & Level Valves

Frequently Asked Questions About Peterbilt 389 Air Springs & Level Valves

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

Air springs (also called air bags) support the weight of the cab or suspension and absorb road shock by inflating and deflating with compressed air. 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 a smooth, controlled ride and proper vehicle height.

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

Common signs include a sagging cab or axle, a rougher or bouncier ride than normal, visible cracks or bulges in the air spring rubber, audible air leaks near the suspension or cab mounts, or the cab not returning to its normal ride height after hitting a bump. If you notice any of these symptoms, it is a good idea to inspect the air springs and level valve for wear, leaks, or damage.

Will these air springs and level valves fit my specific Peterbilt 389 model year?

Peterbilt 389 trucks were built over several years with different cab and suspension configurations, so fitment can vary. Always check the listed part number, OEM cross-reference, and application details on each product page against your truck's specifications before ordering. If you are unsure, our team can help you confirm compatibility using 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?

Basic air spring replacement is a common DIY job for someone comfortable working with air systems and basic hand tools, but level valve replacement and adjustment often requires more precise setup to ensure correct ride height and air travel. If you are not experienced with air suspension systems, we recommend having the work done by a qualified technician to avoid improper leveling or premature part failure.

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

OEM parts are made to the original manufacturer's specifications and are often chosen when exact factory fit and performance are a priority. Aftermarket parts can offer a more budget friendly option and, in many cases, comparable quality and durability. When choosing between the two, consider your budget, how the truck is used, and whether you want a direct OEM match or are open to a reliable aftermarket alternative.