A brake cylinder is a component in a vehicle’s braking system that converts hydraulic pressure from the brake fluid into mechanical movement. This movement pushes the brake pads against the brake disc or brake drum, generating the friction needed to slow down or stop the vehicle.

A brake coupling is a component in the braking system that connects various parts, such as brake lines and hoses, ensuring a secure and leak-proof connection for the brake fluid. Brake couplings are used to direct brake fluid from the master cylinder to the wheel cylinders and brake calipers, playing a crucial role in the functionality of the braking system.