Many people don’t know what shock absorbers are
In their simplest form, shock absorbers are hydraulic pump like devices that help to control the impact and rebound movement of your vehicle’s springs and suspension.
Along with smoothing out bumps and vibrations, shock absorbers help make sure that the vehicle’s tyres remain in contact with the road surface at all times, thus ensuring the safest control and braking response from your vehicle.
A shock absorber is essentially a metal cylinder which is connected at the top to your vehicle’s chassis and at the bottom to each wheel’s axle. The cylinder contains a piston and rod and it’s filled with a special fluid. In the piston are special valves which limit the flow of the fluid, therefore restricting and ‘damping’ the up and down movement of the wheel.
Most modern shock absorbers also have nitrogen gas in the cylinder, which helps with noise and heat reduction.
Why should you get your shock absorbers checked?
Because a shock absorber converts movement into heat through friction, the heat can build up quickly, especially when it’s working harder on bumpy roads. The fluid inside the cylinder is designed to cope with a certain amount of heat, but over time it will become less viscous. The thinner fluid will move through the piston’s valves more easily and the shock absorber’s damping capability will be affected.
As time passes, the moving parts will slowly wear and seals will break down and start to leak. It’s a very gradual process that most drivers won’t even notice.
On average, shock absorbers can be expecetd to last for about 80,000 km, but as a genral rule you should get yours checked every 20,000 km. This is not something that a mechanic will automatically do when you have your car serviced, so remember to ask them to check your shock absorbers when you have your next service.
If you suspect that your shock aborbers may be wearing out and it’s a while until your next service, you can always take you car along to a specialist centre to have them checked. In many cases, a simple check will be free of charge.