The brake master cylinder is the heart of any hydraulic braking system. The master cylinder provides the fluid to pressurize the system in your 1993 Ford E-350. The master cylinder does this in a few simple ways.
The Actuator Rod
The master cylinder is the component in the braking system that is first triggered by pressure on the brake pedal. The actuator rod presses a piston in the master cylinder, which compresses the fluid and sends it on its way through the system.
The Sealed Reservoir
The master cylinder provides a sealed, airtight chamber for the fluid to reside in. This allows it to be pressurized, and does not allow it to escape. The sealed master cylinder reservoir ensures that when the brakes are activated, the piston has enough fluid to deliver to the brake components.
The Return Stroke
The piston also has a return stroke that allows the brake components to release. The reservoir gives the fluid a place to return to as well, so that the brakes can release. Otherwise, once the brakes were engaged, they would stay engaged.
