FREQUENT FAILURES: Pneumatic System Service

Nowadays, the pneumatic system in commercial vehicles is an essential component which is mainly used in braking and suspension systems. These systems need a high quality and clean air.

APM unit assembled in Renault DXi models

It is very common for the air compressors which are mounted in commercial vehicles, to produce dirt (water, oil, etc.). To remove this dirt, valves equipped with a dryer filter are used. In such filter, the dirt produced by the compressor is collected.

It is advisable to replace the filters each 100.000 km or once a year, and it is very important to respect the dates for maintenance services since, otherwise, the dirt may enter the pneumatic system of the truck. The dirt affects the correct performance of the different valves which control the suspension and braking systems.

Moreover, in vehicles working on areas with very low temperatures in the winter, the water by condensation may enter into the pneumatic system preventing the braking system from working properly due to the freezing of some components, with the consequent risk for the vehicle safety.

Air dryer assembled in a Volvo FH/FM model

Trucks manufacturers are increasingly stablishing dates or kilometres for the dryer filters to be replaced. Besides, for the driver’s safety, a warning appears on the instrument cluster indicating that the useful lifetime of the filter has been completed. At that moment, it is necessary to replace the dryer filter and to reset the filter on the truck control unit. To “reset”, it is necessary to have a Jaltest Diagnostics Device. It is the best tool to check the useful lifetime of the dryer filter and to reset the maintenance service when necessary.

It is really important to meet the dates or the kilometres established by manufacturers for the replacement of dryer filters. A poor air quality in the pneumatic system may affect the vehicle safety, as well as increasing the costs since dirt is the main cause for the wearing of the components of the pneumatic system.

Damián Muñoz

Technical Assistance Department