Re: URGENT! Pressure sensor leaking!
OK. See if I've got this straight:
You step on the brake pedal, you have pressure -- that is, the pedal stays UP -- but fluid sprays/dribbles out by the sensor switch.
Silly question: Do you REEEELLY have pressure? Or does the pedal start sinking, e v e r so s l o w l y to the floor?
I should say that I had the same problem on my XF -- exactly the same cylinder ass'y -- but I had very little pressure, the car was almost undrivable. The fluid was coming out of exactly the same place, all over the exhaust manifold.
Now it is important to understand that -- no matter what people wish to believe -- if fluid leaks out of a master cylinder, you do NOT have proper pressure in the system.
The cause in this case is either the pressure cyinder has been scored, or (more likely) the pressure piston has collapsed. It is not worth trying to fix the piston assemby, because you don't know what shape the rest of the master cylinder is in, and it's a bitch of a job anyway. I don't normally like replacing entire assemblies, but in this case I make an exception. Like I said, stopping is very important to me -- especially if I have been bending the law.
So it might look as though I haven't heard a word you said. But fluid leaking out the pressure sensor tells me straight up that you don't have pressure. It's just the way these things work.