Air brakes are so very very simple. They should be an option on 1 tons. Hows a $4,000.00 dollar brake job scare you? All new air cans, slack adjusters, new brake hoses, release / set valves, S cam bushings, anchor bushings, rolls, hardware, brake shoes. Didn't replace drums, and S cams, they are still within specs. Plus the guy doesn't want to spend any more money. Wood chip trailer, it does about 10 to 15 loads a week, he has two trailers.