You might have to trial and error this one. The math would be to find the bore and stroke of the master cylinder to see what volume of fluid it moves in one stroke. I would divide this in half because a full stroke would put the pedal on the floor. A search shows a 2004 S10 to have discs on all four corners which is a two sided sword as discs stay much closer to the rotor than shoes to a drum but then the caliper bore is much bigger than a wheel cylinder bore. A KISS example is a MC with a 1" bore and 2" stroke moves 1.57ci of fluid per stroke of which I'd use 1ci to keep the pedal off the floor. Now IF you can figure the volumes of fluid needed ( pi r squared h) for each caliper to move the pads against the rotors then you will know what size MC is needed. Trial and error is to put it all together, bleed, and see what it has brake wise. If air all out and pedal too low get a bigger bore MC. Too big a MC is like pushing against a rock with little braking happening. As far as line size the above mentioned 1.57ci of fluid per stroke happens in any size line.


































Evan