Hydraulic Brake System Fundamentals

Question 1

I. A force of 800 N is applied to a master cylinder with an area of 8.0 cm2
. The system
pressure developed is:
a) 6400 kPa.
b) 1000 kPa.
c) 0.64 kPa.
d) 1000N.

Answer 1

1. b) 1000 kPa.

Question 2

2. A brake system develops 350 psi on application. The force produced at a caliper
piston with an area of 2. 7 5 in2 is:
a) 127.27 lb.
b) 127.27 psi.
c) 962.5 lb.
d) 962.5 psi.

Answer 2

2. c) 962.5 lb

Question 3

3. A 0.5 cm diameter master cylinder is replaced with a 2.5 cm diameter master
   cylinder. The result is:
   a) more pressure in the system.
   b) more force at the calipers.
   c) less pressure in the system.
   d) more force at the wheel cylinders.

Answer 3

3. c) less pressure in the system.

Question 4

4. One of the reasons DOT 5 brake fluid is not recommended for ABS systems is
because it:
a) has a higher boiling point.
b) has a lower boiling point.
c) will harm painted surfaces.
d) is not hygroscopic.

Answer 4

4. d) not hygroscopic.

Question 5

5. The polyglycol-based brake fluid that has the most stable boiling point is:
   a) DOT 3.
   b) DOT 4.
   c) DOT 5.
   d) DOT 5.1.

Answer 5

5. d) DOT 5.1.

Question 6

6. The hydraulic brake system converts kinetic energy to heat energy through:
   a) friction.
   b) hydraulics.
   c) electronics.
   d) air pressure.

Answer 6

6. a) friction.

Question 7

7. Brake fluid should be stored only in a sealed container because:
   a) the fluid evaporates rapidly.
   b) the fluid is hygroscopic.
   c) the fluid absorbs air.
   d) fluid pressure can escape.

Answer 7

7. b) the fluid is hygroscopic.

Question 8

8. Friction between two sliding surfaces depends on:
   a) the amount of force pressing the two surfaces together.
   b) the temperature of the surfaces in contact.
   c) the coefficient of friction of the materials in contact.
   d) all of the above are correct.

Answer 8

8. d) all of the above are correct.

Question 9

9. The principle of static friction is used in:
   a) the service brake system with the vehicle in motion.
   b) the park brake system.
   c) ABS hydraulics.
   d) the master cylinder system.

Answer 9

9. b) the park brake system.

Question 10

10. Pressure in an enclosed liquid:
    a) depends on the size of the container.
    b) varies with the shape of the container.
    c) acts with equal force on equal areas.
    d) acts parallel to the surface.

Answer 10

10. c) acts with equal force on equal areas.

Question 11

11. The wheel cylinders and calipers convert pressure developed in the system into:
    a) heat.
    b) mechanical force.
    c) directional pressure.
    d) static friction.

Answer 11

11. b) mechanical force.

Question 12

12. The force that tends to resist motion between objects in contact is called:
    a) friction.
    b) pressure.
    c) clamp load.
    d) drag.

Answer 12

12. a) friction.