Self-explanatory. Running v.1.4.5. (I have only tried it on Spruce tanks)

I'll see if I can duplicate it. Type of tank shouldn't matter btw.

Works fine for me, have you tried in an instance with only agricraft?
http://puu.sh/luvZ5/190d5b3d30.png
http://puu.sh/luw0u/3d986e3abe.jpg

Youll have to add half of your mods to the instance, check it. If it happens then keep that half and repeat, if not, repeat with the other half. And so on until you pinpointed what caused it.

It works properly on a clean instance, Mhm... No idea which mod breaks it. Should I close the issue since we don't know which mod is problematic?

Yeah I thought about this but that's 100+ mods. Not today :)