Outer Limits 4x4 Board

hey everyone i have a 1989 hilux with a vr v6 motor an a (r151 i think) it hase a new master cylinder new exedy sports tuff clutch slave is fine so i have not replaced it and a ajustable slave shaft now the problem i am having is when you bleed the clutch it will not ingauge . then if you adjust the slave shaft verry verry tight you can drive it you can put it in 5th at 50kms an stand on the loud pedal it does not slip at all now this is all good to drive but it only lasted a week an then only when is hot it was hard an some times impossible to get in to gear but when cold is ok . so i pulled the master cylinder out an discovered that the master cylinder was not yousing all of its avalabel travel so i made a longer shaft on me old boys bosses lathe an this fixed the problem for a ferther week but now it is back to the same thing again can anyone help please sorry for the long post but i wanted yous to no everything to give me the best advice cheers daniel