You should remove the master cylinder reservoir cap and diaphragm, install suitable fittings to the master cylinder ports, install transparent hoses to the fittings installed to the master cylinder ports, fill the master cylinder reservoir, ensure that the ends of the transparent hoses running into the master cylinder reservoir are fully submerged in the brake fluid, remove the transparent hoses from the master cylinder reservoir, install the master cylinder reservoir cap and diaphragm, remove the fittings with the transparent hoses from the master cylinder ports and then remove the master cylinder from the vise.
By BobGM Specialist
01/11/2022