How Does a Master Cylinder Work?

How Does a Master Cylinder Work?

The dominate cylinder is a critical part to your vehicle ’ sulfur braking system. Understanding the function of the overlord cylinder can help you determine if you want to replace it and what to look for in a successor. Let ’ s take a brief overview of a brake system, then get into contingent about the role of the master cylinder. We ’ ll look at unmarried and dual reservoir cylinders, have a bun in the oven size, and all the components of the passkey to help you make the best choice for your vehicle .

Braking System Overview

Whether you employ an all-disc organization, a disc/drum combination, or an all-drum apparatus, the function of the master cylinder remains the lapp .
The dissemble of braking begins when you depress the brake bicycle. The headmaster cylinder uses that coerce to push a piston and send hydraulic fluid through the brake lines to each individual brake. Pistons inside of a digest that are located on each of the four brakes, fill with brake fluid and engage the pads or shoes and embrace against the rotor or brake drum and stop your vehicle

Bạn đang đọc: How Does a Master Cylinder Work?

Simply put, the mechanical coerce exerted on the brake pedal by your foot gets converted into hydraulic pressure by the overlord cylinder. That press sends the fluid through your bracken lines and engages the pistons at each of the four wheels, therefore activating the brake calipers and slowing or stopping your fomite .

Single vs. Dual Reservoir Master Cylinders

There are two types of overlord cylinders : unmarried reservoir and double reservoir. Single reservoir systems feed both the front and rear brakes from a single reservoir and brake line while double reservoir systems have one reservoir feeding the front brakes while the second reservoir feeds the rear brakes through two wholly discriminate brake lines .
The failsafe of the dual reservoir headmaster cylinder ensures that, in the consequence of a malfunction, your chances of having some work brakes are better than they are with a unmarried reservoir master .

Bore Size

In summation to the reservoirs, affair will be affected by bore size. Bore size can range from 7/8 ” to 1-1/4 ” and will affect pedal travel distance and feat. In other words, a smaller have a bun in the oven size will increase blackmail and decrease the come of effort required by you to stop your vehicle .
“Decreasing master cylinder bore size will decrease your pedal effort and increase your pedal travel. Conversely, a larger bore in your car’s master cylinder will, with all other components being consistent, increase your pedal effort and decrease your pedal travel. As with some other brake parts purchases, this comes down to your preference for how the brakes “feel” underfoot when you are driving.”
– MPBrakes General Manager, Mark Chichester

Components of a Master Cylinder

nowadays that we know the two main types, let ’ s dig into the main parts of the master and how it works to regulate your braking system .


The reservoir, or reservoirs, are used to firm the bracken fluid. In a double reservoir system, the reservoirs can be of adequate size but in other overcome cylinders, one of the reservoir might be smaller. No matter the size, one of the reservoirs feeds the front brakes, while the other reservoir feeds the raise brakes. it does matter which of the reservoir is used to feed the front or rear and that is dependent on the actual overlord cylinder as there is not a standard.



Machined into the center of the headmaster cylinder body is the actual bore of the maestro cylinder which houses the pistons. The pushrod from the brake pedal or the booster pushes against the piston housed inside this yield. When the bicycle is pressed, the piston is moved inside the bore and pulls fluid from the reservoir and compresses that fluid frankincense creating hydraulic imperativeness to the rest of the organization. The harder the pedal is pushed and the far the piston travels will create more line pressure .


The leap is a component inside the maestro cylinder bear that provides resistance when applying the brake pedal point and besides allows the piston and brake pedal to return to their original position after the brakes are no farseeing engaged .

How Do You Know When the Master Cylinder Has Gone Bad?

There are internal and external seals inside the master cylinder. The dislocation of these seals over time results in brake fluid leaks outside of the unit or brake lines. typically, if your victor cylinder needs to be replaced, your brake pedal will feel mushy or spongy. In some cases, the bracken pedal point will even drop or fall to the floor when the vehicle comes to a complete stop .

Features to Consider

In addition to bore size, which is typically selected based on brake type, consider which side of the master cylinder would be ideal for interface localization when place and installing the master. An adjustable pushrod attachment may work for your vehicle equally well .

Customer Example: 1969 Ford Mustang with 4 Wheel Disc Brakes

not long ago, we received a request for help from the owner of a 1969 Ford Mustang who was looking for a Ford maestro cylinder to use for his 4-wheel magnetic disk brakes set up .
In this event, with the manual phonograph record brakes both front man and rear on the customer ‘s ’69 Mustang, we recommend MPB part phone number MC11378M. This headmaster cylinder has a 1 ” wear and ports on the left-hand side of the dominate cylinder, which should work well for his fomite.

Xem thêm: Wikipedia

This specific master cylinder has been greatly successful when used by many of our customers who drive four-wheel disk cars, as measured by vehicle owners reporting comfortable brake pedal change of location and required pedal feat along with our own testing of components on a vehicle .
A brake system ’ s master cylinder is a critical part that transfers the forcible violence into hydraulic push, sending brake fluid through the brake lines to engage the calipers and stop your vehicle. It ’ mho important to consider master cylinder size, port placement, and bore size when choosing the one that will fit your car the best .

We’re Happy to Help

As you can see, there are early vehicle-specific factors to consider when selecting your fresh overlord cylinder. If you ’ re confused or torn between several options, please drop us a occupation. We ’ five hundred be happy to help you figure out what separate will be best for you .

reference :
Category : Car Brakes