The pan I ran (somewhat smaller than the 657e above, a ts24 euclid) never had working brakes, and we ran it for about 3000hrs that way without incident, including the time the operator got tired of waiting for the lowboy and just drove it down the road to the next job site, about 15 miles. DOT didn't catch him until he was within 2 miles of the new job. The only way to slow that beast down was to lower the cutting edge, and it was SHARP by the time he got stopped for the DOT. The two tickets were for overweight (2 axles, 25tons dry weight) and no tag. It was never scary to operate, because you never stopped all day long except for lunch and quittin' time. This tractor used linked loading, where two tractors would link nose to tail and one loaded while the other helped pull, all 4 motors at full throttle in lowest gear. That was two 12v72's and two 8v72 Detroit two stroke diesels at full bellow.

Rule 1, don't get in front of moving heavy metal.