Summer's heat, dust and stop-and-go traffic will take their toll on your vehicle. Add the effects of last winter, and you could be poised for a breakdown. You can lessen the odds of mechanical failure through periodic maintenance.
Air conditioning - A marginally operating system will fail in hot weather. Have the system examined by a qualified technician.
Cooling system - The greatest cause of summer breakdowns is overheating. The cooling system should be completely flushed and refilled about every 24 months. The level, condition and concentration of the coolant should be checked. (A 50/50 mix of antifreeze and water is usually recommended.) DIYers, never remove the radiator cap until the engine has thoroughly cooled. The tightness and condition of drive belts, clamps and hoses should be checked by a professional.
Oil - Change your oil and oil filter as specified in your manual - more often (every 3,000 miles) if you make frequent short jaunts, extended trips with lots of luggage or tow a trailer.
Engine performance - Replace other filters (air, fuel, PCV, etc.) as recommended - more often in dusty conditions. Get engine driveability problems (hard starts, rough idling, stalling, diminished power, etc.) corrected at a good shop.
Windshield wipers - A dirty windshield causes eye fatigue and can pose a safety hazard. Replace worn blades and get plenty of windshield washer solvent.
Tires - Have your tires rotated about every 5,000 miles. Check tire pressures once a month; let the tires cool down first. Don't forget your spare, and be sure your jack is in good condition.
Brakes - Brakes should be inspected as recommended in your manual, or sooner if you notice pulsations, grabbing, noises or longer stopping distance. Minor brake problems should be corrected promptly.
Lights - Inspect all lights and bulbs; replace burned out bulbs; periodically clean dirt and insects from all lenses.