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3.2 Common Fault Analysis and Troubleshooting Methods of Air Suspension

Time：2025-10-13 Edit：Admin Views：108

Fault Location and Symptoms

Fault and Cause Analysis

Troubleshooting Method

Air Spring

Faults

Air spring cannot be inflated

Air spring elasticity decreases

① Insufficient air supply pressure from the main vehicle;

② Air spring or control air circuit malfunction;

③ Height control valve installed incorrectly, other valves damaged or improperly installed;

④ Water accumulation in the air tank not discharged in time, causing water buildup inside the air spring.

① Ensure main vehicle air pressure reaches 0.6 MPa;

② Inspect and repair the control air circuit;

③ Check and adjust or replace damaged valves;

④ Regularly drain the air tank and remove water from the air spring.

Air spring damaged

Piston cracked

① Hard debris (e.g., gravel) enters between air spring and piston, causing abrasion;

② Sharp objects puncture the air spring;

③ Improper H-value adjustment;

④ Severe overloading;

⑤ Clearance around the air spring less than 25 mm;

⑥ Oil or grease on the air spring causes premature aging;

⑦ The positioning sleeve on the leaf spring bracket breaks or the rubber bushing inside the guide leaf spring ear is damaged, causing axle misalignment and friction between the air spring and tire.

① Clean the air spring regularly;

② Adjust H-value properly;

③ Load within rated capacity;

④ Adjust or redesign the air suspension installation;

⑤ Replace the rubber bushing and adjust the welded positioning sleeve;

⑥ Replace the air spring.

Cracks or air leakage at top edge or piston joint

① Air supply pressure too high, serious overloading;

② Shock absorber failure, limit steel wire rope damaged or incorrect model, causing excessive air spring extension.

① Check pressure regulator valve, replace if faulty;

② Check limit steel wire rope and shock absorber, replace if damaged.

Overextended load air spring

① Limit components damaged;

② Height control valve improperly adjusted.

① Replace limit steel wire rope or components;

② Adjust height valve to installation height.

Guide Leaf

Spring and

Bracket Faults

Guide leaf spring bracket cracked / Hinge bolt worn

① Reinforcement parts not installed as required;

② Severe overloading;

③ Poor road conditions;

④ Hinge bolts of leaf spring not tightened in time.

① Install reinforcement parts as specified;

② Load within rated capacity;

③ Tighten bolts periodically with specified torque;

④ Replace guide leaf spring and hinge bolts.

Guide leaf spring damaged

① Severe overloading;

② Poor road conditions;

③ Improper H-value adjustment;

④ Shock absorber failure;

⑤ Leaf spring damage.

① Load within rated capacity;

② Drive at low speed;

③ Adjust H-value;

④ Replace shock absorber;

⑤ Replace leaf spring.

Axle displacement

① U-bolts not tightened in time;

② Poor road conditions.

① Tighten U-bolts with specified torque;

② Drive at low speed.

Axle misalignment / Trailer drifts

① Check if guide leaf spring or bracket connection bolts or bushings are worn;

② AD1 line or wheelbase variation.

① Replace bolts or bushings;

② Tighten lock nuts to specified torque;

③ Re-adjust AD1 line or wheelbase.

Shock Absorber

and Rubber

Component Faults

Shock absorber overextended

Limit components damaged.

Replace limit steel wire rope or components.

Shock absorber leakage

① Incorrect installation (e.g., upside down, wrong connection position);

② Wrong shock absorber model;

③ Shock absorber worn.

① Install correctly;

② Replace shock absorber.

Rubber bushing cracked

① Severe overloading;

② Poor bonding between rubber and metal core or bad vulcanization (product quality issue);

③ Pin bolt over-tightened causing bushing deformation;

④ Use of lubricating grease causes premature aging.

① Load within rated capacity;

② Replace shock absorber.

Inner hole of guide leaf spring bushing worn

① Pin bolt torque insufficient, causing looseness;

② Bushing deformation;

③ Normal wear.

① Tighten lock bolts;

② Replace bushing.

Control

System Faults

Height control valve slow response or not working

① Insufficient main vehicle air pressure;

② Air line blockage, foreign matter in height valve body or poor air flow;

③ Frozen air lines due to water accumulation in tank, freezing under cold weather;

④ Valve body damaged.

① Check pressure protection valve and main vehicle air pressure;

② Clean or replace air lines, clean air filter;

③ Defrost and drain air tank;

④ Replace height control valve.

Vehicle leaning / tilting

① Improper height valve adjustment causes deviation from designed H-value, resulting in vehicle tilting;

② Height valve fault or blocked air line causes deflated air spring.

① Adjust H-value to specified position;

② Clean air lines.

Relief valve cannot close properly / cannot maintain air pressure

① Dirt inside relief valve;

② Moisture in air tank freezes relief valve in cold weather;

③ Relief valve adjustment screw loose.

① Clean relief valve;

② Defrost and drain air tank;

③ Adjust and tighten relief valve screw.

Control air circuit leakage

① Poor air line routing causes abrasion and leakage;

② Damaged air line fittings;

③ Folded air lines obstruct air flow.

① Route air lines properly and replace damaged ones;

② Replace damaged fittings;

③ Inspect all air lines.

Previous：2.9 Tightening Torque Table for Fasteners Next：Ⅳ. Air Suspension Maintenance Instructions

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