Frequently Asked Questions About Peterbilt 388 Air Springs & Level Valves

Will these air springs and level valves fit my specific year Peterbilt 388?

Most air springs and level valves for the Peterbilt 388 are compatible with model years 2005-2015. However, there can be variations based on your truck's suspension configuration (Airglide, Airliner, or Low Air Leaf). Always verify your suspension type and provide your VIN when ordering to ensure proper fitment. Some applications may require different mounting brackets depending on whether you have a day cab or sleeper configuration.

How difficult is it to install air springs and level valves on a Peterbilt 388?

Installation typically takes 2-4 hours per axle for experienced mechanics. The most challenging part is often accessing the upper mounting bolts in tight spaces. You'll need basic hand tools, jack stands, and ideally an impact wrench. Common issues include rusted mounting hardware that may need cutting and replacement. We recommend having new mounting bolts on hand. Professional installation is advised if you're not comfortable working with air systems, as improper installation can lead to dangerous ride height issues.

What are the signs that my air springs or level valves need replacement?

Replace air springs if you notice: visible cracks or dry rot in the rubber, air leaks (hissing sounds or inability to maintain ride height), uneven ride height side-to-side, or excessive bouncing. Level valves should be replaced if the truck won't level properly, takes too long to adjust height, or if you hear constant air bleeding. A common test is to mark your ride height, drive for 30 minutes, and check if it has changed - any variation indicates a failing component.

What's the difference between OEM and aftermarket air springs for the 388?

OEM Firestone and Goodyear air springs typically last 300,000-500,000 miles and maintain consistent ride quality. Quality aftermarket options from brands like Hendrickson or Watson & Chalin offer similar performance at 20-30% less cost. The main differences are warranty length (OEM usually 2-3 years vs. aftermarket 1-2 years) and rubber compound quality. Avoid extremely cheap imports as they often fail within 100,000 miles and may not maintain proper ride height under load.

Can I replace just one air spring or should I do them in pairs?

While you can technically replace a single failed air spring, we strongly recommend replacing them in pairs (both sides of the same axle). Air springs lose elasticity over time, so pairing a new spring with an old one often results in uneven ride height and handling issues. The cost difference is minimal when considering labor, and paired replacement typically extends the life of both components. If budget is a concern, at minimum replace both on the drive axle first, as these bear the most weight.