How to Assemble a Bus Suspension Air Spring
I. Preparation
Safety Measures: Park the bus on a flat surface. Use a jack and stands to securely support the frame and ensure the suspension is completely unloaded. Disconnect the power supply and release the compressed air from the air tank.
II. Removing the Old Air Spring
Releasing Air Pressure: Disconnect the air spring's air hose connector and clamp it with air hose pliers to prevent air leaks. Depressurize the air slowly to avoid popping components.
Removing the Mounting Components: Remove the upper and lower air spring mounting bolts/nuts (note that the spring may still have tension). If using a leaf spring assist mechanism, loosen the seat bolts first.
III. Installing the New Air Spring
Positioning and Aligning: Position the new air spring in its mounting position, ensuring that the upper and lower bushing holes align with the frame and suspension arm. Avoid twisting or stretching the air hose.
Securing Bolts: Hand-tighten all bolts first to ensure proper thread engagement. Tighten in steps according to the manufacturer's torque setting (typically 50-100 Nm), staggering the bolts to avoid uneven loading.
Connecting the Air Line: Connect the air line, ensure the O-rings and seals are intact, and apply a small amount of grease to prevent leaks. Use clamps or threaded fasteners (if applicable).
IV. Testing and Adjustment
Inflation and Leak Check: Start the engine and inflate the air system to the operating pressure (usually 5-8 bar). Spray the joints and spring surfaces with soapy water and check for bubbles.
Height Adjustment: Some buses require height adjustment via a sensor or manual valve. Refer to the service manual for standard values. Test the suspension travel to ensure there is no interference.
Road Test: Test for abnormal noise at low speed and check the shock absorption effect. Review the bolt torque and air pressure.
V. Precautions
Overpressure is strictly prohibited: The inflation pressure must not exceed the spring calibration value.
Regular Inspection: Rubber bladders are prone to aging; inspect for cracks or wear every six months.
Professional Operation: If electronic control systems (such as ECAS) are involved, specialized equipment is required.
VI. Common Problems
Air Leaks: Replace the seals or tighten the air line.
Uneven height: Check for a sensor or air line blockage.
Unusual noise: Verify that the spring is installed correctly and that the bushing is not worn.
