The Mystery began with the rebuild of my Clutch Slave Cylinder. In the instructions Girling has you apply grease provided by them to the area behind the dust cover. I did exactly what they asked. After roughly a month or so the clutch started to not disengage properly. I took this as air in the lines. After removing the slave and inspecting it I came to find the grease had turned hard and sticky. Not what you’d expect. I disassembled and cleaned everything and reassembled the unit. After this the cylinder seemed to slide fine and would hold air pressure when I covered the fluid inlet with my thumb. From this I’m assuming it should work fine now that the sludge has been removed. Has anyone experienced this before?