The Rebbe once related a story about Reb Izek Humlor (from his Sefarim is printed the Safer Pelach Harimon and there are others just not printed.) He was a Bechur (first born) a Bechur must make a Siyum every Erev Peasach. I’m not sure it could be that he fasted too. The way it was by the Rebbe my father in-law was that he would make a Siyum and then all those who would also make a Siyum on that day he’d call them into his office, have them make the siyum in front of him. Then he would fast the whole day. How Reb Izek conducted himself if he fasted or not, I don’t know. But he would make a Siyum on the whole Shas aside for all his learning he’d do, this is one thing he would do special for Erev Peasach. After he had run away to the Alter Rebbe, the custom in those days was that the father would rip Kriah R”L and sit Shiva etc. For Peasach Reb Aizik went home, when Erev Peasach came around and he made a Siyum on the whole Shas, “OY” his father said he ran away and is still making a Siyum on the whole Shas I regret all that I have done and they reunited in peace.
(Maaseh Rav Tape #2 Side 1 the seventh sicha)
