Delete all your old messages to free space on your phone. 1  Go to Settings --> Messages. 2  Scroll down to Message History. Here, you can choose to delete all messages older than 30 days, or all messages older than a year old.  Confirm that you want to delete the old messages and attachments.
Well, the master cylinder is tasked with supplying hydraulic pressure to the braking system. So when you initially step on the brake pedal the linkage activates a piston within the system and this piston then displaces hydraulic fluid.
The brakes work because we cannot compress brake fluid. We apply pressure to a piston in a cylinder and this reduces the fluid capacity. Brake fluid under pressure now moves to other cylinders connected to the system. Pressure applied to the first piston transfers to the second. This force moves the second piston.