Q: All of a sudden the clutch pedal has no resistance and I am unable to put it in any gear while running the engine. 1999 Dodge Dakota

Hello - as you suspect, the clutch hydraulics have likely failed. Check for low clutch fluid (may share a reservoir with the brake master cylinder). If the fluid is low, check for brake fluid at the clutch slave cylinder or under the truck at that point. It is possible, but unlikely, that the failure is with the clutch pressure plate. Most likely the clutch slave cylinder has worn out, leaked fluid out, and now air is in the clutch line. Sometimes, however, the clutch master cylinder fails, and leaks fluid onto the carpet under the drivers foot area. I recommend a clutch isn’t working inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.