The procedure is to plug the outlet ports, mount the master cylinder in a vise with the front end slightly down, fill the master cylinder reservoir with clean brake fluid, stroke the primary piston about 25 mm (1 inch) several times using a smooth round-end tool, reposition the master cylinder in the vise with the front end tilted slightly up, then stroke the primary piston about 25 mm (1 inch) several times again, then reposition the master cylinder in the vise, loosen the plugs in the outlet ports one at a time, tighten the plug(s) before allowing the piston to return to its original position and fill the master cylinder reservoir with clean brake fluid.
By BobGM Specialist
28/10/2022