Auto repair expert Deanna Sclar believes that a monthly five-minute check under the hood of your car could eliminate up to 70 percent of highway breakdowns.

For this preventive maintenance, she advises checking:

The radiator for sufficient water or coolant. If there is rust, the radiator may need flushing. You can do that job yourself cheaply and quickly, she says, for about $4. It might cost you $25 at the garage.

The fan belt, for fraying.

The battery, for sufficient water. Remove "the lovely white and blue deposits" on the top of the terminals so the cables won't corrode.

Hoses. If they are "leaking, bulgy, soft and squishy, or hard and brittle" they probably need replacing.

Oil level.

Automatic transmission fluid. People often are as surprised as she was, she says, to learn that there is a transmission dipstick to show fluid level.

Brake fluid.

Power-steering fluid.

Windshield-washer fluid.

Wiring. If the wires feel hard or brittle or appear corroded, or bright metal shows through the insulation, she advises getting them replaced at the garage until you become a real expert.

Tire pressure. She suggests keeping the pressure 2 to 4 pounds less than that recommended on the tires.

If all this sounds like a lot of work, Sclar says that a TV demonstration she cut the time down to two minutes.