The Mechanical brake that is installed on our Motor Home doesn't really seem to be anything but that. I really don't think it would stop the rig, and I certainly would'n depend on it to park on an extreme slope. It is connected behind the transmission on the drive shaft, and not to any of the actual wheel brakes. The old EMERGENCY brake systems were attached by cable to both of the rear wheels, and could easily lock up both, or either of them. Used them many times to slow a car without the brake lights coming on, especially if there was a police car behind me. BTW, they still work pretty good to get a tailgater off your backend, but it can get your rear end smashed also. Procedure is slow, downshift, gently raise brake handle, then drop handle and stomp the gas pedal to get out or the way. And if it is a new car and looks well insured, pull the handle again real quick and collect the insurance money. Note: beware nasty old farts driving beat up old cars with dents in the back.
