Air spring failures resulting from over-extension are most commonly seen on lift axle applications and par-particularly on trucks or tractors used in severe on/off road service such as construction, logging or quarrying.

On those types of vehicles, check to see if the shock absorbers need to be repaired, replaced or are missing, which is not an unusual occurrence. Although shocks were not designed as axle travel limiting devices, they are often the only defence against over-extension.

Solution: Bring the air spring back into the proper operating zone by: limiting axle travel, checking leveling valve for proper operation, adjusting leveling valve to proper ride height and checking for proper application

Over extension of the air spring results from unrestrained travel of the axle, which eventually tears the bellow away from the metal top plate or the bottom piston.