The clutch pedal on my 2000 Accent (manual hydraulic) went completely dead today going down a rather steep hill in third gear, that is when I engaged the pedal to glide it was completely loose. I was able to brake and when I leveled at the bottom of the hill the clutch was back to its normal self (after a few secs). All the gears are tight in the box and it shifts smooth. At first I thought it was simply low on fluid but it is full. Only other thing I can think of is a small leak in master causing it to leak fluid back to reservoir going down hills, clutch is firm all other times. Any other ideas?
I gather that when ypu couldn’t get the pedal “to engage” you felt no resistance during its downward stroke. On idea might be that the fluid boiled in the line going to the slave cylinder and later cooled enough to return regular function. You might inspect the routing of the line from master cylinder to slave cylinder to see if it come close to any exhaust manifold or pipes. If so move the line or insulate. Otherwise, flush out the old fluid and replace it with fresh dry fluid.