Yep, That fixed it... I must have removed a pipe and replaced it in the wrong spot between train loads... (which is very possible)
Thank you so much for your reply and solving my issue!

I just got my oil refinery set up for the first time (took some figuring out). My first train load (Fluid Wagon) worked smoothly. The crude oil unloaded went through the basic refinery (I don't have advanced oils yet). But, my second train load was only able to unload a little bit of crude before it...