It leaks everywhere under my truck and leaves pools of liquid when i park! What is it and what is its purpose?

 

Clutch slave cyl.

 

Is purpose in engaging/disengaging clutch fork. There's a hard line running between the clutch slave and clutch master cylinder. The clutch system does not hold much fluid so if it was leaking "pools" you would know because you'd have no clutch.

It's most likely your rear main seal leaking oil and your flywheel is making a mess in the bellhousing, causing oil to leak out the clutch fork boot. My guess anyway