To test shock damper performance in post-1995 vehicles, bounce each corner gently. If the car stops bouncing with a just a little rebound, shocks are good. If it keeps bouncing, you need new shock absorbers. All you need to do is look for any leaks, holes, or serious damage in the shock absorbers. Replace them with fresh ones if any of these problems show up. Unscrew the top cap, then push and pull the piston rod up and down for easy operation. Get a new piston rod if you feel any hard or soft spots. You need to pump up the piston rod before install to get fresh grease into the seals. Start by unwinding the lug nuts that hold the front wheel, lift the entire vehicle safely, and take off the wheel. When lifting an Automatic Ride Control vehicle, only do it if you've turned off the switch that controls the air suspension. Unplug the electric wires and pipes from the shock absorber. Keep holding the shaft when you unscrew its top bolt. To take away front left height sensors from ARC systems, follow the instructions closely. To take out the shock on 1995 and later models, take off the control arm nuts, then push the shock down a bit to remove it from the brackets. We do the opposite of what we did to take off the wheel - put it back on, making sure our new nuts and bolts get tightened to the right amount of pressure, then screw on the wheel and tighten the lug nuts at the correct pressure.