I thought the whole idea of modern split circuit brakes is that if there was a fluid leak, there should always be just enough fluid in the other circuit for limited braking and a few applications, albeit with a very soggy and low pedal. Otherwise what is the point of split circuit brakes? A 1985 4/4 is long after the split circuit legislation came in. Even my 1976 Midas GT has split circuit brakes but maybe because that was originally one of the two factory built cars and not a kit.
I suppose that is why competition cars are always recommended to have separate fluid chambers or at least a chamber with a separating wall for about 1/3rd of the way up, so you always have some fluid in one circuit but only one place to fill. That is how it works on my 1977 Porsche 911 RSR which has one partially split filling pot feeding two separate master cylinders with a Bowden cable adjustable threaded balance bar between them.
Wilson
