A hydraulic jack takes a lot of the work out of lifting a heavy item, such as a riding lawn mower. However, a jack must be positioned properly or the lawn mower risks crashing down. This not only damages the mower but can cause you severe injury. Jack placement varies, depending on whether you need to lift the mower's front or back end. Generally, you lift a mower to change a tire, so place the jack as near to the tire as possible.
Drive the lawn mower to a flat and open area. Park the lawn mower, set the parking brake and disconnect the spark plug. Slide two 2-by-4 boards in front of the tires that will remain on the ground. For example, when you change a rear tire, place the two boards in front of the front tires.
Slide the hydraulic jack underneath the riding lawn mower, near the appropriate tire. Lie on your back and look underneath the lawn mower to see if there is a jack guard -- a square metal piece attached to the mower's frame.
Center the hydraulic jack underneath the guard. If your lawn mower does not have a guard, center the jack underneath the lawn mower's frame. Never lift a lawn mower from underneath the mower housing.
Crank the hydraulic jack handle to lift the lawn mower. Continue to crank until the tire spins freely. Lift the lawn mower only as high as necessary to prevent damaging the frame.