Kenworth W900A Air Springs & Level Valves

Frequently Asked Questions About Kenworth W900A Air Springs & Level Valves

What do air springs and level valves actually do on my W900A?

Air springs (also called air bags) support the weight of the cab or rear suspension and absorb road shock, while the level valve (height control valve) automatically adjusts air pressure in the springs to keep the truck riding at the correct height as load and road conditions change. Together, these components keep your ride stable and help protect the frame and drivetrain from excess vibration and impact.

How do I know if my air spring or level valve is failing?

Common signs include a sagging cab or rear end, an uneven ride height side to side, excessive bouncing or harshness over bumps, audible air leaks near the suspension or cab mounts, or the compressor cycling more often than normal. If the truck sits noticeably lower on one side or takes longer than usual to level out after a load change, the level valve linkage or valve itself is a likely culprit.

Will these air springs and level valves fit my specific W900A?

Kenworth used different air spring and level valve setups depending on model year, cab suspension type, and axle configuration, so fitment can vary even within the W900A line. Always check the part number, mounting bracket style, and valve arm length against your truck's original component before ordering, and compare OEM numbers when available to confirm an exact match.

Can I install a replacement air spring or level valve myself?

Many owner-operators and shop techs replace these parts with basic hand tools, a jack, and a way to safely support the cab or frame while the old air spring is removed. That said, the level valve linkage arm needs to be set precisely to the correct length and angle, since even a small adjustment error will cause the truck to ride too high or too low. If you are not comfortable with air suspension systems or do not have a way to verify ride height afterward, it is worth having a qualified diesel technician handle the install.

What material and quality differences should I look for between air spring and level valve options?

Air springs are typically built with reinforced rubber bladders designed to handle constant pressure cycling and road debris, so look for products that specify durable, heavy duty construction rather than a generic replacement. Level valves are usually metal bodied with internal seals that need to hold up to constant air flow, so a valve from a reputable manufacturer with consistent quality control will generally hold up better and leak less over time than an unbranded budget option. When possible, matching OEM specifications or choosing parts from well known suspension component brands is the safest way to ensure long term reliability.