# What does a bigger bore master cylinder do?

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## What does a bigger bore master cylinder do?

While a larger master cylinder creates a larger displacement, it takes more force to create the same pressure as a smaller bore. While a larger master cylinder will take up system slack with less pedal stroke, it will take more force to create the same system pressure.

What size bore master cylinder for drum brakes?

The most important factor in how your brakes function is the bore size of the master cylinder. This will directly affect how your system feels and all manufactures offer a variety of choices. The most common sizes are 3/4-inch, 7/8-inch, 1-inch and 1-1/8-inch, although other sizes are often offered.

### What size clutch master cylinder do I need?

The basic rule is the smaller the bore size the easier the pedal feel, as long as you’re keeping the motion ratio of the pedal in the same spot. Most manufacturers of master cylinders will recommend around a 6:1 pedal ratio for the best feel.

Does the size of a brake booster matter?

BOOSTER SIZE is an important consideration. Power brake boosters require 17″ of vacuum or more to function properly. Smaller brake boosters are great for tight spaces, but may require up to 22″ of vacuum in order to function properly.

## How far does a master cylinder piston travel?

Typically, a master cylinder has approximately 1-1/2-inch to 1-3/4-inch of stroke (travel).

How do I know my master cylinder bore size?

To get to this number you use the formula for Area which is: Area = 3.14 (Pi) multiplied by the radius squared. So you calculate the radius of 1” bore which is simply half of the diameter which equals . 5” (half an inch). The result is that a 1” master cylinder has a radius of half an inch.

### How is clutch pedal ratio calculated?

On average, clutch pedal ratios range from 5.0-7.0:1. To determine the pedal ratio, measure the pedal pad to the pivot, then measure from the master cylinder rod mount to the pivot and divide the second measurement into the first. The higher the ratio, the more leverage you will have over the clutch.

How do I know what size brake booster I need?

To determine the assist provided by the brake booster, a very simplified equation is to multiply atmospheric conditions by the diameter of the booster and multiple that by the number of diaphragms in the booster. The resulting number is the amount of assist the booster provides.

## How much does it cost to replace brake booster and master cylinder?

To have your brake booster replaced, you are looking at a cost somewhere between \$300 and \$700 for the majority of cars. There are some outliers, of course, but on average, you will pay somewhere in that range. Labor costs tend to range between \$100 and \$170, while parts can cost as little as \$150 or as much as \$500.

How do you check a master cylinder?

Apply pressure to the brake pedal until it comes to a stop and then hold the pedal there, sustaining the pressure. If moments after the brake pedal has come to its initial stop it begins to drop down again slowly, then the master cylinder is not functioning properly and will most likely need to be replaced.