Most service facilities are equipped to perform these tests. Hoses - If hoses in the vehicle are cracked, soft, or are in poor condition, they should be replaced. Cooling system - Maintaining the proper engine coolant level is important. Over time, it's natural for engine coolant to become contaminated, so the system should be flushed and replenished periodically as recommended by the manufacturer - typically every three years or 36,000 miles. Any cracks from decay in the hoses could spell trouble.
Oily substances found near the joints where the hoses meet parts indicate a leak.
Even the smallest leak at a joint can shut down your air-conditioning system. Your service technician can test for this. It may be the result of a blown fuse, which indicates a problem somewhere else in the car.