The clutch on my 97 4.0l 4WD 5 speed will not release. I can only get it into gear by turning the engine off, then depressing the clutch and selecting a gear. Then I can start it and it will creep slightly forward and then when I let up on the clutch it will move forward or backward but I cannot then change gears. With engine running in neutral, gears clash with pedal fully depressed. The fluid level in the master cylinder is normal and steady but there is also some evidence of leakage on the slave and minor leakage on the hydraulic line. The garage I had it towed first said that the entire clutch mechanism AND hydraulics need to be replaced, but they have not done any work on it; they just want to order the parts and replace everything. When pressed about how they diagnosed that they said; based on the mileage (160K), "they guarantee it". The car is on an island and repair costs are sky high and it is starting to just along the rocker panels. They quoted me $1700.00 for complete replacement. On my 1990, I went 200k miles w the original clutch (lots of highway miles on both cars).

1. Is it reasonable to think that it might be just the hydraulics?
2. Are there significant extra costs associated with starting with just the master/slave assembly and seeing if that works?
3. Is there a way to tell if it is the hydraulics or the actual clutch plate/mechanism without dropping the transmission.

Thanks for your help people.