Though most of the candidates were attracted to this question, their performance was very poor as they could not give the required responses to the various parts of the question. The required responses to the various part of the question are:
(a) When the brake is depressed, brake fluid is displaced from the master cylinder through the pipelines to the wheel cylinders. The wheel cylinder piston and brake shoes that bear on the piston move out. Thus the friction linings of the shoes are brought into contact with the drum thereby restricting its rotation.
(b) The advantages of a hydraulic brake as compared to a mechanical braking
system are:
- it is self compensating;
- it is self lubricating;
- it has less chance of seizure;
- its rate of wear is very low;
- it has less noise due to friction and rattling.
(c) leading shoe is the one that moves out in the same direction as
the direction of rotation of the drum.
(ii) trailing shoe is the one that moves against the direction of
rotation of the drum.
