I'm sure what I'm doing wrong is simple, but I cant figure it out. Buildcraft can pump both in and out fine, but getLiquid() always returns null. If I change the tank line to be something like "public final LiquidTank InternalTank = new LiquidTank(Block.waterStill.blockID, MAX_LIQUID, MAX_LIQUID);" then getLiquid() always returns the starting value even when the liquid is drained.
My code: http://mqdomain.com/TileEntityHPCrucible.java