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

What years and models are these air springs and level valves compatible with?

These air springs and level valves are specifically designed for Peterbilt 389 glider kits from 2007 to present. They're also compatible with standard Peterbilt 389 models from the same years. However, compatibility can vary based on your specific suspension setup, particularly if you have aftermarket modifications. We recommend checking your current part numbers or contacting our support team with your VIN for exact fitment verification.

How difficult is the installation process, and what tools do I need?

Installation typically takes 2-4 hours per axle for experienced mechanics. You'll need basic hand tools including wrenches (typically 3/4", 7/8", and 1-1/8"), air line cutters, and thread sealant. The most challenging part is usually accessing the upper mounting bolts and ensuring proper air line routing. Many customers report that having a second person helps significantly when aligning the springs. Professional installation is recommended if you're not comfortable working with air systems, as improper installation can lead to ride height issues or air leaks.

What's the difference between OEM and aftermarket air springs for my 389 glider?

OEM air springs typically use a two-ply rubber construction with reinforced steel girdle rings, while quality aftermarket options often feature similar or upgraded materials at a lower price point. The main differences you'll notice are in longevity (OEM typically lasting 300,000-500,000 miles vs 200,000-400,000 for aftermarket) and warranty coverage. Aftermarket springs from reputable manufacturers like Firestone or ContiTech perform comparably to OEM for most applications. The key is avoiding ultra-cheap options that use single-ply construction or inferior rubber compounds.

How do I know if my level valve needs replacement versus just adjustment?

A level valve needs replacement if you notice constant air bleeding, inability to maintain ride height even after adjustment, or visible damage to the valve body or linkage. Common symptoms of a failing valve include one side sitting lower than the other, excessive air consumption, or the truck not returning to proper height after loading/unloading. Before replacing, try adjusting the linkage arm - many issues are solved by proper adjustment. The adjustment procedure involves loosening the locknut and turning the arm until the desired ride height is achieved with normal load.

Can I upgrade to a different ride height or firmness with these components?

Yes, you can modify ride characteristics within limits. Extended-stroke air springs can provide 1-2 inches of additional height, which many drivers prefer for improved ground clearance. For firmness, you can adjust air pressure within the manufacturer's specified range (typically 60-100 PSI for most applications). However, extreme modifications can affect handling and component life. If you want significant height changes, you may need to replace both the air springs and level valves as a matched set, and possibly modify the linkage arms to maintain proper geometry.