Drove to Melbourne last Friday week, real hot day (high 30s), had traveled 300ks and had our first stop pretty well. Pulled over, engine still running, depressed clutch pedal and there was no resistance for say first 70mm (top travel) and was a bit clunky at that 70mm point where the pedal just took up hydraulic pressure. It also became a bit harder than normal to depress the pedal to the floor after several consecutive pumps of the pedal.
Fluid level was OK, may need changing, actually looked a bit discolored (dark) and clutch slave cyl and rod looked and seemed OK. Did check to see if the slave cyl was not getting too hot, eg: maybe the exhaust heat shield was not in place but all was OK.
Stayed put for a while (40min), kick had gone out of the heat of day as Sun was nearly setting. Drove off and all seemed to operate fine and has done so since (traveled 1200ks after problem).
Any thoughts?