Drove truck out of town, once on highway for about 20 min, clutch had no pressure, would go all the way to firewall with no resistance. Then once i slowed down or pumped the clutch it would come back and act completely fine when driving around town. Checked clutch fluid and no drop or signs of a leak. Now I am hearing a grinding/scrapping sound when in neutral and clutch is released. When clutch is pressed down sound goes away. Also having a hard time putting into second gear and keep hearing that same noise when in any gear while driving. I have no idea where to start troubleshooting this problem. Any advice would be appreciated.