cars have dual circuit brakes which inherently have a back-up, when you
step on the brake pedal in a 6x6, you truly have a single lifeline.
The accompanying information is equally applicable to M54 and
M809-series 5-ton trucks. Detailed instructions are given in your
vehicle’s manual, available from numerous vendors, and with which
each vehicle owner should become familiar before sliding behind the
wheel for the first time.
The air-hydraulic cylinder is essentially equivalent to the power
brake booster found on most automobiles. However, rather than
relying on engine vacuum for the power assist as do cars, these
units get their power assist from compressed air, supplied by the
engine. One side of the unit is charged with air, the other holds
brake fluid. Air tanks hold a reserve supply, but even if this supply
is exhausted, the truck’s brakes still work, albeit without the power
assist.
Even though this truck had been thoroughly gone through
relatively recently, the extended period of storage without