Cooling System

The primary job of the cooling system is to cool the engine and to keep it from overheating. Another important job of the cooling system is to allow the engine to heat up as quickly as possible and then to keep the engine at a constant temperature because when the engine is cold its components wear out faster and the engine is less efficient and emits more pollution.

There are two types of cooling systems used in modern cars: air-cooled and liquid-cooled systems.

Most cars are equipped with liquid-cooled systems. The coolant flows around the engine and then passes through the radiator. Then it passes through the water pump and flows around the engine again. There are some stages of the cooling process. First, the liquid flows around the engine. The engine is cooled and the liquid is heated. The hot water enters the radiator through the upper (top) hose. Then it flows down through the radiator and here it is cooled by air. The air is pulled by a fan. This fan is turned by a belt which is driven by the engine. The cooled liquid leaves the radiator through the lower (bottom) hose. The coolant is pumped around the engine again.

Modern cars operate in a wide variety of temperatures. So the fluid used to cool the engine must have a very low freezing point and a high boiling point and hold a lot of heat. Water freezes at too high a temperature to be used in car engines. The coolant used in most cars is a mixture of water and ethylene glycol called antifreeze. The recommended ratio is fifty-fifty. In other words, one part of antifreeze and one part of water.

VI. Scan the text “Steering System” to find answers to these questions.

1. What is a steering wheel used for?

2. What kinds of steering systems are there?

3. What is the hydraulic power steering?

4. How does the electric power steering work?

Дата добавления: 2014-10-15