I've always used 1/4' on drum and 3/16 on disc.
Line size is doesn't make a difference when applying or to create line pressure. Using larger size for wheel cylinder is because you need the fluid to leave the cylinder faster than on a disc which doesn't retrace as far. Wheel cylinders eject more fluid when the springs retrace the pistons so larger lines, 1/4", make that easier and less likely to hang momentarily. Disc piston doesn't retract that much and the disc run out will force the fluid out as far as needed. If you look on a old C50 C60 it will have 5/16 line and huge cylinder. if you have 3/16 on their now go with that it may have small cylinders and larger in the back
Last edited by thoroco; 11/30/2014 10:31 PM.
