II. Look through the text again and answer the following questions:

1. What was the first for stopping vehicles?

2. What were mechanical brakes then replaced by?

3. Why have disc brakes become very popular?

4. Did ABS become a standard equipment on passenger cars?

5. What are parking brakes?

III. Match the words with their definitions and make up your own sentences with these words:

brake	a) having the shape of one half of a circle;
semicircular	b) a device for stopping or slowing a car;
to adjust	c) to fix smth in position for use, display;
to mount	d) to adapt smth.;
hydraulic systems	e) the system of gears by which power is passed from the engine to the wheels;
pedal	f) a round plate or short cylinder that fits closely inside a tube and moves up and down inside it;
piston	g) a flat bar that drives or controls a machine;
transmissions	h) a metal support;
caliper	i) a bar or rod joining parts of a machine or transmitting power in a machine;
drive shaft	j) a system of a mechanism operated by liquid moving in this way;

IV. Find the information about new brake performance. While looking for information you are free to use the internet sites given below as well as any other online resources.

Make a short presentation in front of the class.

Resources recommended:

www.automobile.ru

www.wikeipedia.com

www.drive.ru

www.autogazeta.com

Text 19

1. Read the text about power steering gear. Steering

Power steering gear was developed to solve the steadily increasing steering problems. Power steering was first applied to heavy trucks and military vehicles early in the 1930s, and hundreds of patents were granted for devices to help the driver turn the steering wheel. Most of the proposed devices were hydraulic; some were electrical and some mechanical. A pump driven by the engine maintains the hydraulic fluid under pressure. A valve with a sensing device allows the fluid to enter and leave the power cylinder as necessary. Speed-sensitive variable effective ratio systems are available on a few cars to provide reduced steering effort for low-speed maneuvers and more sensitive lower ratios for high-speed highway steering.

Communication with the hydraulic cylinder goes through a two-way restrictor valve. This valve limits the rate of movement of the plunger in the cylinder, since fluid must be pushed into the sphere when the body descends and returned when it rises. This damping action thus controls the motion of the wheel with respect to the sprung portion of the vehicle supported by the spring.

So-called “active suspensions” incorporate a microprocessor to vary the orifice size of the restrictor valve in a hydraulic suspension or shock absorber. This changes the effective spring rate. Control inputs may be vehicle speed, load, acceleration, lateral force, or a driver preference.