Study of Pneumatic Rubber Valves Degradation by Formation of Esters in “Fresh” and “Used” Lubricating Oil

A great deal of problems occurring with several commercial vehicle marks world-wide is the frequent failure in rubber material of the pneumatic rubber of brake circuits. The most frequent fails observed in the field are: valves stuck, rubber wear off, rubber rupture and softening degradation. In order to determine the causes, studies were developed in laboratory following the formation of esters, searching for its effects and submitting the pneumatic rubber valves to direct contact and finally comparing the data with valves aged on the field.