The brake pedal is directly attached to the master cylinder. Pedal pulsation, excessive pedal travel, a “soft” or “hard” pedal can be indicators of serious problems, including a leak in the hydraulic system, low fluid levels, or unevenly worn shoes or pads
Power brake booster:
The power brake booster is available in most vehicles. The Booster increases break pedal force. It links the brake pedal apply system to the Master Cylinder Assembly.
Master cylinder is a tank which holds brake fluid. When the driver depresses the brake pedal, the master cylinder forces fluid to each of the vehicle's wheels through steel brake lines and flexible reinforced rubber hoses.
When the driver puts pressure on the brake pedal, it is the brake fluid which transmits energy to the caliper and wheel cylinder pistons. Brake fluid absorbs moisture and can damage paint. So it is extremely important and it should not be over looked and caution should be taken when handling brake fluid.
Hoses & Steel lines:
The pressure produced in the master cylinder is transmitted by brake hoses and steel lines. From the steel lines, brake fluid pressure is channeled through Balance Control Systems.
Balance control / Warning system:
It is a combination valve located on or near the master cylinder or in the steel lines between calipers and wheel cylinders. This system ensures that brakes apply quickly, simultaneously, and at a balanced pressure for safest operation.
Hardware consists of a variety of parts designed to assist in restoring the brake system to "Like New Performance". Caliper anti-rattle clips, seals, pins, and dust boots; along with drum shoe return springs, hold down springs, and adjuster assemblies, help to maintain consistent, balanced braking.
It contains fluid-activated pistons that push the shoes against the drums to slow the wheels. Wheel Cylinder is considered as major source for brake problem. If fluid leaks from wheel cylinder then it will reduce the efficiency of the braking system.
Combination Valve is comprised of a metering valve, proportioning valve, and brake warning light and it regulates the amount of pressure on each set of wheels and ensures that both front and rear brakes are applied at the same time.