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.
Drum brake master cylinders have residual valve(s) built into the master cylinder. This is needed to maintain pressure against the cup seals in the wheel cylinders. If you are using a disc brake master cylinder or after market you will need to install a 10 pound residual valve for the drum brakes.