shocks provide resistance by forcing hydraulic fluid (oil) through valves in the piston as it moves up and down. Because the oil cannot be compressed, only a certain amount of fluid can be forced through these valves, which creates resistance to the vehicle movement. Premium shocks and struts are superior to regular hydraulic shocks because air in the shock is replaced by pressurized nitrogen gas. This advancement in technology prevents bubbles from forming in the hydraulic fluid. These bubbles, called foaming, reduces the ability of shocks to provide resistance and prevent bounce. Gas shocks also quicken the response of a shock's movement thereby increasing comfort and control under all conditions.
The operating principle of direct-acting hydraulic shock absorbers is in forcing fluid through restricting openings in the valves. This restricted flow serves to slow down and control rapid movement in the car springs as they react to road irregularities. Usually, fluid flow through the pistons is controlled by spring-loaded valves and the hydraulic shock absorber automatically adapts to the severity of the shock. If the axle moves slowly, resistance to the flow of fluid will be light. If it is rapid or violent, the resistance is stronger, since more time is required to force fluid through the openings. By these actions and reactions, the shock absorbers permit a soft ride over small bumps and provide firm control over spring action for cushioning large bumps. The double-acting units must be effective in both directions because spring rebound can be almost as violent as the original action that compressed the shock absorber.
Do you experience excessive bounce (3 or more bounces) when crossing an intersection or dip?When stopping quickly, does your vehicle rock back and forth several times?While applying your brakes firmly at higher speeds, does your vehicle have a tendency to drift left or right?When changing lanes quickly does your vehicle rock or sway from side to side?On a tight curve like a freeway ramp, does your vehicle lean and sway giving it an uneasy and disconnected feeling?
If yes to any of the questions above, it is worth getting your shockies checked!