Parking brake leaking.

[jeffiyoung]

Hi I have a hydraulic leak from where it seems parking brake is. When you pull up on the parking brake it pulls 2 plungers out of the rear axle one on the left side and one on the right side. The left side is leaking and when the parking brake is released the leaking left side doesn't seem to close all the way. Is this a o ring leaking or how is this supposed to be sealed? I've attached pictures of both the leaking and non leaking side any and all help would be greatly appreciated.