Hydraulic-over-air relay valves are designed to convert hydraulic-modulated input pressure to a proportional output air pressure. The valves are suited for on and off-highway applications ...

Air-brake systems are subject to excessive oil contamination. As reliable as they are, vehicle compressors can and do fail. One form of announcing this problem to the diagnostic technician is the ...

Paccar Inc., one of several manufacturers whose trucks are affected by problems with a Bendix air-brake valve, has issued a recall that includes 21 Kenworth and Peterbilt models. Meanwhile, the other ...