The rust on the rear end assembly is so severe that the brakes are compromised, and the back up emergency brake system has failed. the rust on the differential housing is so severe that the fluid has leaked out and the gears are at risk for catastrophic failure. the spring mounts to the axles are also rusting severely, creating a risk of lost control should either side break away. it takes great effort when braking, and the vehicle pulls severely due to rust causing the loss of integrity of the braking system. the brakes, once applied, do not release evenly, creating uneven brake wear, shuddering and shaking, resulting in poor control, excessive and uneven tire wear, i.e., tires locked and dragging, scalloping. on wet, and i fear, icey, surfaces, the truck has slid sideways due to one or more wheels not releasing.