Air Spring

Air Spring — Comfort and Balance Element of the Suspension System

Air spring is a bellows-type component placed between the chassis and axle in the suspension system of heavy commercial vehicles, filled with pressurized air. As part of the suspension group, it softens impacts and vibrations from the road surface, protecting both the vehicle body and the transported load. Unlike conventional spring systems operating at fixed stiffness, the air pressure inside can be continuously adjusted, providing a load-adaptive carrying height; the cabin and chassis level thus remain balanced independently of the load.

The category includes complete single-bellows and double-bellows air spring groups, bellows rubber, piston, upper and lower connection caps, mounting plates, bolt sets and seal-felt sets, and a wide range of products such as air connection nipples and support brackets. These parts can be used separately both for complete group replacement and for renewal of only worn components.

• Complete single-bellows and double-bellows air spring groups
• Bellows rubber, piston and lower-upper connection caps
• Mounting plate, bolt set and seal-felt sets
• Air connection nipple and support brackets

Air spring is offered with size and connection options varying according to different models and axle types of major truck and bus brands; therefore, before replacement, the vehicle chassis information and the connection type of the existing part should be used as reference to select the correct product. Considering the whole suspension system, air spring does not work alone but together with components such as the load-level-sensing level valve, the cylinder transmitting this signal, the coupling transmitting the movement, and the bearing bracket connecting the axle to the chassis; a malfunction in any of these parts can also shorten the service life of the air spring. Regular visual inspection, checking the bellows surface for cracks or leaks, and monitoring the air system pressure balance is the most practical way to detect problems before they grow.

Frequently Asked Questions

What is an air spring? A bellows-type suspension element located between the chassis and axle, which carries load by filling with pressurized air and dampens road shocks.

What are the signs of air spring failure? Excessive shaking during driving, the vehicle body lowering toward one side, visible cracks on the bellows surface or whistling-like air leaks are the most common symptoms.

When is an air spring replaced? Replacement is necessary when the bellows rubber shows tears, cuts or excessive wear, when constant air leaks are detected, or when the vehicle level cannot be maintained under load.

How to select the correct air spring? By comparing the vehicle model, axle location, bellows connection type and dimensions of the existing part, a product that perfectly fits the suspension group should be preferred.

Why does air leak from the air spring? Tears in the bellows rubber surface, loosened connection caps or worn seals and felts can cause pressurized air to leak.

How does the air spring relate to other suspension components? The load-level-sensing level valve, the cylinder transmitting the signal and the coupling, together with the bearing bracket connecting the axle to the chassis, work with the air spring to maintain balanced vehicle height.

Should other parts be checked when replacing the air spring? When installing the new part, the mounting plate, connection bolts, seal-felt sets and the level valve adjustment must also be thoroughly reviewed.