Brake Work Example 19

ACT Work Keys Level: 7
NATEF Task(s): V.B.1

Problem:

A driver puts a force of 360 Newtons on a brake pedal. The brake pedal ratio is 8:1, and the master cylinder diameter is 3 cm. The diameter of the front wheel cylinder caliper piston is 3.2 cm. What is the force that the front wheel caliper piston develops?

Solution:

1. Force on master cylinder = Force on brake pedal × Brake pedal lever ratio
   1/8 = 360/c
   c = (360)(8) = 2880 Newtons

2. Area of master cylinder piston = diameter² × 0.7857.065 cm² = 32 × 0.785C.

3. Pressure developed within the master cylinder = Force/Area
   407.64 N/cm² = (2880)/(7.085)

4. Area of front wheel caliper piston = diameter² × 0.785
   8.04 cm² (3.2)² × 0.785

5. Force resulting from the pressure within the master cylinder = Pressure × Area
   3277.4 Newtons = (407.65 N/cm²)/(8.04 cm²)

The force that the front wheel caliper piston develops is 3277.4 Newtons.