After installing a new clutch, slave and master recently with an H55 upgrade on a '83 FJ60, have had a problem with the clutch pedal getting hard and notchy as truck warms up. When the truck is started cold, the clutch feels perfect. As truck warms to operating temperature, the clutch will get firmer and like it is grabbing something (like there are notches) as you depress the pedal. Have bled the line several times with same pattern occurring. Can't find any visible oil leaks either side of firewall or where hoses join slave/master and hard line. Fluid level in master reservoir remains unchanged. Does this sound like a slave cylinder or master issue? Guess it is possible either of these new units could have a defective seal?