It’s impossible to fix something without understanding how it’s supposed to work. Brake system repair decisions can be difficult to make, and costly to execute, without a basic understanding of system ...

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, including ...

The following was published in CCJ's Air Brake Book, 11th edition, sponsored by SilverbackHD. CCJ's Air Brake Book is a complementary industry resource, courtesy of our partnership with SilverbackHD, ...

Descending a long downgrade can trigger a runaway even when your brake system is in good working order. Here’s why. The treadle valve, under the pedal, sends only a small air signal. It activates a ...

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 ...