[Whaler]

Richard that was my first thought too...chewed up particles of O-ring/seals will give you that blackness in the fluid...
Definitely stay away from Silicone as well as that to will degrade and breakdown in the system..which it sounds like you have.
As for no pressure..I would suspect you have lost your sealing ability to pressurize using the pedal.

Is the fluid in the remote/ reservoir contaminated as well??

Whaler