Spring brakes are SUPPOSED to stop the truck,when you lose air pressure,(usually 20 p.S.I.,and below). I drove a 1978 IHC S-1900 tandem straight truck,and it didn't have an air drier. During the Summer,when the weather got humid,I'd stop,and drain the tanks every couple of hours. The compressor gets hot,and causes condensation in the air lines. i was working for an ice company,and the busiest day was the 4th of July. I was assigned the S2200,(semi tractor,with an air drier),/reefer trailer,that day,since I loaded twice as much ice,to cover all of my "stops". I instructed the driver,assigned to "my" 1900,to make sure and "bleed" the air tanks. He didn't take the warning seriously. Going down a 3-mile stretch of 5% grade,he had plenty of pedal,(STANDING on it),but, NO BRAKES!! He pulled the emergency,and parking brakes,(they both pop-out),heard the swoosh,like they applied,but kept gaining speed. He didn't know how to shift the 10 speed "Ranger",either,so he was out-of gear,besides! The truck came back on the tail of a wrecker,and it was TOTALED! He rolled it on its side at the bottom of the hill,(T-intersection). Luckily the driver survived with just a few bumps and bruises. But to be SAFE,with a full air system,PLEASE install an air drier!
