This vac truck tried backing into a steep driveway but high centered on the hydraulic oil tank mounting brackets. Most drivers would have pulled back out onto the highway but he was afraid of rupturing the oil tank. He called the PD for traffic control until I could get there. I would lift the front off the ground and the driver would release the brake and ease the truck forward until the tank almost touched the ground then lift again/ease forward until we got the oil tank past the driveway hump