A Buick shock absorber is the auto part that provides your car with a smooth ride which is beneficial to both the passengers of the vehicle and the car itself. This is the part of your vehicle that reduces the upward and downward motion created when passing over an obstacle in the road, and the spring on your car reduces bounces in the body because of this up and down motion. The best test to see if your shock absorber is working properly or needs replacing is still the same test that?s continuously been used for over 50 years. Pressure should be applied to the corner or end of the fender of your Buick so it depresses the body of the car. When the pressure is released, the body of your car should rise then settle back into its normal resting position. If the body travels up and down 2 or more times before settling down, then the shock absorber should be replaced because it is worn out. The replacement of just one Buick shock absorber is not recommended. If one is failing then so are the others or they are close to it. This will give your Buick the right parts so a smooth ride can be obtained. Unless your car has MacPherson struts on the front, there are 4 shock absorbers on your car. There is another check you can perform when inspecting the shock absorbers on your Buick. This auto part is a sealed hydraulic unit. If any fluid is seen on the shaft of the shock, then failure is eminent and replacement of this part is required. If the other shocks are relatively new, then the replacing of only one would be appropriate.