With oil not much can be done, it can soak into the pad material depending on the material used. My friend got oil splashed by a broken hose from a car that was on a drag strip in the next lane over & he had to change his pads out to get stopping power back.

Interestingly enough, yesterday i rode a bike i bought for a friend years ago. Its way too small and needs its shift mechanism tuned up, but i used it to ride out into the park nearby & observe the effects of local flooding. The rim brakes worked pretty well even when 100% submerged in silty water....




Water was over the path past here & didnt wanna risk getting stuck in the muck.


Rode through this... it was 3-4 inches deep.


I may put a disc on rear of my new bike, but not sure yet.

- Andy