Pulsing brake lever

[BigT]

Howdy gents,
I took the sleds out for a first ride of the season Saturday and found my brake lever pulsing on my 2010 M8. I could actually see the lever moving while applying brake pressure.
When i got back to the truck (about 1/2 mile or so) I lifted the hood and found dark grease splattered on top of the engine and splashed onto the inside of the hood. The splatter was just right of center on the hood. i first suspected the diamond drive but after a quick visual inspection I found it to look ok and does not appear to have any grease/oil on or around it. A quick inspection of the top side of the belly pan does not appear to have much grease/oil residue.
Any ideas before I tear into this thing? First plan is to pull the diamond drive and check it out. Any other thoughts?
Thanks in advance,

BigT

 

[ultrasks700]

it sounds like you have an exhaust leak, that is really the only thing that would make a mess like you described. Look around the Y pipe area that donut gasket there likes to leak. Did you take a look at youre rotor yet? it might be warped

 

[Hardass]

i concur exhaust i had that happen to me and my y pipe was split on the back of the y

 

[Dam Dave]

brake rotor is warped