Symptoms of a Bad or Failing Shock Absorber
1. Vibrations While Driving - If the valving or piston seal inside the shock is wearing out then it may allow fluid to flow uncontrolled. Thereby every tiny bump in the road causes an overreaction that you will feel with your hands on the steering wheel.
2. Swerving or Nose Diving While Braking - The slightest steering wheel turn or brake leads to extreme movement of the piston within the cylinder. For example, when braking, the car will shift farther forward than anticipated causing a nose-dive. This adds time and extends the stopping distance required.
3. Uneven Tire Wear - A worn shock is unable to keep the tire firmly on the road surface. The part of the tire that is in contact with the road will wear. As the tire rotates, this contact area constantly changes with road speed, frequency of bounce, etc.
4. Leaking Fluid - Sometimes the seals will begin to leak and the fluid run down the side of the shock towards the ground. This will cause a loss in the ability of the shock to perform its function as there will be less and less fluid in the chamber to work with.
5. Cracked Bushing at Attachment Points - The shock has points at each end that allow it to be bolted to the vehicle. If those rubber bushings of attachment points crack or break out then a tapping will be heard as the vehicle is driving over bumps.