[Walt Fricke]

Mickey
Leaking brake hydraulic parts usually result in a soft pedal, not a hard one, so I am not surprised that replacing your MC didn't change this.

Are you sure that the difference here is really the change from the boosted brakes of the SC and 996 to the plain vanilla brakes of the 912?

If your steel brake lines have not rusted internally (or externally other than superficially, I don't see why you would need to replace them. It is rather a PITA to fish the one for the rears through the tunnel, although replacing the other shorter parts is easy, and those are the ones most likely to have some external corrosion. My '68 912 (for a long time converted to six cylinders and a race car) has the long line original. I may have replaced some of the shorter ones, since I have a dual MC setup.

I can't tell from the parts catalog if the '68 only came with the single MC setup (just one pressure chamber for all four brakes), or the tandem cylinder (one chamber for the fronts, one for the rear, so if one system fails you have some braking from the other). If a single cylinder, be good to replace with the tandem.

The early 914s came with a 17mm MC. Switching to a 19mm MC will stiffen the pedal. I don't know what MC your car came with, but if a 17 and it now has the 19 (I think all the dual circuit ones are 19s, but not sure), that would make the pedal harder.