A clutch servo brake chamber is a device that is used in heavy vehicles, such as trucks and buses, to assist in the operation of the clutch. The brake chamber is a cylinder that contains a piston, which is connected to the clutch pedal. When the pedal is pressed, the piston pushes on the brake fluid, which in turn activates the clutch. The brake chamber is typically located on the firewall, near the brake master cylinder. It is an important part of the vehicle's braking system, as it helps to smooth out the engagement and disengagement of the clutch, which can help to prevent damage to the transmission.