Posted by Willy-N on Thursday, December 29, 2005 at 3:35PM :
In Reply to: Re: 46' 1 1/2 ton w/ factory air brakes by me. posted by Tom Petroff on Thursday, December 29, 2005 at 10:52AM :
Vacuum is harder to make and store in large quanities. Once you reach a perfect vacuum thats all you can make so you would need larger tanks to store it for more volume. With air pressure you can keep raising the pressure and store more volume of it. So air presure won the battle. The Pressure and Vacuum was used to hold the brakes off not on. They use a spring to apply the brakes in newer trucks and air to compress the spring and relise the brakes. That is why when the low air presure light and buzzer comes on you want to get off the road fast befor they lock up. Mark H.
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