The master cylinder is an essential element of your car’s brake system. It transforms the force you apply to the pedal into hydraulic pressure that applies brakes.
The master cylinder contains fluid, two pistons (primary and secondary), as well as springs that push them together. When you release your brakes, these same springs return the pistons to their starting positions.
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Brake Lines
Similar to how your heart pumps blood out of your arteries, the master cylinder in your car also circulates brake fluid through its brake lines. This system plays a significant role in keeping your vehicle secure and preventing accidents.
Brake fluid enters the master cylinder through two lines that lead to each front and rear wheel. When the driver applies brake pressure, two pistons inside the master cylinder are squeezed together, pressurizing them and sending pressure down each line to each wheel.
The master cylinder also features a channel that counteracts the vacuum created in the piston chamber when you release the brake pedal, helping prevent an abrupt drop in pressure.
Once installed, it’s necessary to bleed it in order to eliminate any air bubbles that may have formed inside. Do this by pressing on the plunger on the back of the master cylinder.
Master Cylinder
The master cylinder is the backbone of your vehicle’s brake system. It acts like a foot-operated pump, pushing brake fluid from its reservoir through steel lines to calipers and wheel cylinders.
It also transfers brake pressure from your pedal to the calipers, where it is applied to the rotor. Most vehicles utilize dual-cylinder master cylinders with separate front and rear hydraulic lines for extra security in case one line breaks.
Master cylinders feature two compression chambers, similar to syringes, that generate hydraulic pressure. These are machined into the center of a housing and also include a spring, rubber cup, and piston for added safety.
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Brake Booster
Brake boosters are essential parts of modern cars that provide extra force when you press down on the brake pedal. Without one, you would need to apply significantly more pressure than usual in order to make your brakes work – which can be quite a difficult feat!
When you step on the brake pedal, it presses a diaphragm against a rod that transfers force to the master cylinder. Additionally, this pulls on the rod further, increasing resistance against its piston. All together this combined effort can quickly and smoothly slow your vehicle down.
Once you release the brake pedal after braking, the diaphragm moves away from driver’s side (vacuum side). This pushes open one way vacuum valve and draws air out of chamber while maintaining vacuum inside booster.
Brake Pedal
When you press the brake pedal, a piston is driven through the master cylinder and hydraulic pressure is transmitted along brake lines to each wheel’s calipers. This causes them to clamp against rotors and slow your car down as you apply pressure.
Ideal, your brake lines should have some wiggle room so they can flex and move with the rest of your system. Without enough slack, they may snap and break, making it impossible to stop your car.
Brake line deterioration is often the result of moisture and road salt that corrodes steel tubing, allowing fluid to leak out and damage both the master cylinder and calipers. This may make your brake pedal feel soft or low, as well as making brakes less responsive when you step on them.
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For optimal pedal firmness and reduced brake drag, it is recommended that you replace your stock brake hoses with stainless steel braid protected flexible Teflon hoses. These will enhance brake performance and outlive OEM hoses.