Checking shock absorbers

Part 1. Preparation and safety

Objective

• Check the serviceability of the shock absorbers and struts.

Personal safety

Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection - such as rubber gloves and barrier cream
• Respiratory equipment - such as face masks and valved respirators

If you are not certain what is appropriate or required, ask your supervisor.

Safety check

• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.

Points to note

• Shock absorbers and struts are located near each wheel and protect the passenger compartment from bumps.
• Many of today's vehicles are equipped with strut type suspension instead of conventional shock absorbers, but testing either system involves the same procedure.
• If a vehicle has adjustable shock absorbers, make sure that the shock absorber adjustments are the same for the left and right-hand side.
• Some shock absorbers contain pressurized gas. To prevent personal injury, do not puncture or incinerate these shock absorbers.

Part 2: Step-by-step instruction

1. Check shock absorbers and struts
   The simplest form of suspension test is known as a “bounce” test. Lean heavily on the fender or place your weight on a bumper. Release it suddenly and watch what happens. If the vehicle rebounds continually, you need to replace the shock absorbers. If the shock absorbers are performing well, the car will rebound once only, and then slowly return to its original position. While driving, the same test can be performed by stopping the vehicle suddenly from a very low speed. If the car “bounces” up and down a couple of times when coming to rest, you need to replace the shock absorbers.
2. Visually inspect shock absorbers
   Visually inspect the shock absorber mounting points for security and corrosion and note any wet looking patches on the sides of the shock absorbers. This is a common indicator that the strut or shock absorber needs replacing because of a fluid leak.
3. Check strut upper mounting
   Pay particular attention to the top strut mounting during the bounce test. Place your hand on top of the mounting during the bounce test. Any noise or movement in the mounting could indicate the need to replace the component. If you do feel movement, hear noise or see signs of leakage, report it to your supervisor.