YM, Are You Sure?
There are two systems on commercial diesel engines. I have never heard of bleeding off condensation of the fuel system, but there is an air brake system the requires regular bleeding, or at least an automatic bleed system.
Are you sure you're referencing the fuel and not brakes systems?
"We drive into the future using only our rearview mirror."
- Marshall McLuhan -
Northern California Wine Country...
"Turbos whistle, grapes wine..."