Freightliner SD 108-122 Air Springs & Level Valves

Frequently Asked Questions About Freightliner SD 108-122 Air Springs & Level Valves

What do air springs and level valves actually do on my Freightliner SD 108-122?

Air springs (also called air bags) are part of the truck's suspension system, supporting the frame and cab or axle while absorbing road shock. Level valves work alongside the air springs to automatically adjust air pressure, keeping the truck riding at the correct height as load conditions change. Together, these components help maintain a stable, controlled ride and protect the chassis and drivetrain from excess stress.

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

Common signs include a sagging or uneven ride height, a rough or bouncy ride, visible cracks or bulges in the air spring's rubber bellows, audible air leaks near the suspension, or the truck settling slowly after being parked. If you notice any of these symptoms, it is a good idea to inspect the air spring and level valve assembly before the issue affects handling or causes further wear on other suspension parts.

Will these air springs and level valves fit my specific Freightliner SD model?

Products listed in this category are intended for Freightliner SD 108 and SD 122 trucks, but exact fitment can vary depending on axle position (front or rear), suspension type, and model year. Always check the part number and listed specifications against your truck's OEM part or service manual before ordering to confirm a proper match.

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

Basic air spring replacement is a common maintenance task that many experienced technicians and fleet mechanics handle in-house, typically involving supporting the axle, releasing air pressure, and swapping the old spring for the new one. Level valve adjustment and replacement require correct linkage positioning to ensure accurate ride height. If you are not familiar with suspension systems or do not have the right tools and lift equipment, we recommend having the job done by a qualified diesel truck technician.

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

OEM parts are made to match the original specifications of your Freightliner SD, while aftermarket parts are manufactured by third-party companies to fit the same application, often at a lower price point. Both can provide reliable performance, but it is important to check that any aftermarket part meets or exceeds OEM specifications for load capacity and durability. If you are unsure which option is right for your truck, our team can help you compare choices based on your budget and usage.