"If shock absorbers were like air filters or tires, you wouldn't hesitate to inspect them," say automotive engineers. But a worn shock or strut, unlike a clogged filter or a flat tire, won't disable the car. But it can do worse. Because of the loss of ride control, even one bad shock absorber can lead to an accident.

Shock absorbers and struts, part of the complex steering/suspension system, usually wear gradually. The vehicle owner may not realize how the ride or handling characteristics have deteriorated until an emergency arises.

Many owners, in fact, do not realize these components require periodic checking and replacement.

To increase car owner awareness, these are the answers to the five most commonly asked questions about shock absorbers and struts.

Q. Will new shocks cure the weak springs on my car?

A. No. Shock absorbers cannot replace springs. Special load carrying or booster shocks, however, can help support limited overload weight.

Q. Isn't the shock absorber's function to smooth out the ride?

A. That's only part of its job. Shock absorbers (and/or struts) do a lot more than that. They improve handling by reducing from end drive when braking. They also add to safety by controlling body sway and roll on turns even on smooth highways. Good shocks also prevent wheel hop, which can lead to loss of control.

Q. Don't the new gas-charged shocks and struts last longer because there is no fluid to leak out?

A. Gas-charged shocks and struts do last longer than their predecessors, but they still have fluid. One purpose of the gas, usually nitrogen, is to prevent aeration of the fluid which causes foaming. Foaming of the fluid hinders shock absorber performance.

The gas charge also improves internal valving of the shock, improving both stability and ride.

NOTE: When either shocks or struts are replaced, they should be replaced in pairs for proper handling characteristics.

Q. Do I need to have the wheels re-aligned after having new shock absorbers installed?

A. No. But you'll probably need wheel alignment service if you've had new struts installed. That's because struts are an integral part of the suspension system.

Q. Can I get my worn shocks repaired?

A. No. These are sealed units which must be replaced. Some struts, however, can be rebuilt with a replacement cartridges, (essentially the shock absorber component within the unit) which can be installed when the old on is worn out.