or spouse. Even if the vehicle will be only moved around on your own
property, it is prudent to first attend to the braking system. Family
members, pets and belongings can all suffer if you procrastinate in this
area, as can the whole hobby, which is under increasing scrutiny. A
single tragic accident due to brake failure could easily make national
headlines and lead to the restriction of the use of those vehicles already
in the hands of collectors.
The master cylinder on M54 and M809-series 5-ton trucks is located
beneath an access panel in the driver’s side floorboard, as it is on
many vintage vehicles. The master cylinder cap has a pipe elbow in
its top, to which a vent line is connected. The vent line must be
removed before the cap can be unscrewed. Once this cap was
removed, it was evident that not only was there no fluid in the
master cylinder, but the cylinder was heavily rusted. This damage
was not a result of decades of neglect — this master cylinder had
been installed new less than five years before. Master cylinders for
these trucks are rebuildable, but they are also inexpensive and
abundant.THE BRAKE SYSTEM
There are five major components of the service brake system on 2-^1 ⁄ 2