Maybe the lube spray did something? If it's silicon or somerthing maybe could cause issues?
I just drown mine in circuit board cleaner.
I swapped the clutch and brake pots, and lo and behold, now the brake still didn't work but the clutch did, so the pot was ok all along. I then re-soldered the brake pot and it now seems to be working again. I always said it didn't really feel like a spiking pot, because it was 99% solid. Maybe a wire was dodgy. Anyway, it's all working again, with clutch and brake pots swapped. But I still don't know now if I've fixed my original brake problem!