Thanks all. I top it up, pumped the air out and now I have brakes. However, in the future before I take this beast out on the road I would like to inspect the brakes. Mine is a 48 two ton and you have to pull the hubs just to take the drums off. There doesn't appear to be a leak, that I can find, but where did the fluid go???????????.

A day without laughter is a day wasted- Charlie Chaplin
When wrestling a grizzly bear, you have to keep at it until the bear gets tired, not when you get tired.
1948 Chevy 2-Ton