Such as the title,i used the defualt texture to open the game.I placed some tank and filled some liquid. When I changed the texturepack to the "soartex fanver"(64x texturepack),the tank will displayed some wrong texture.
Similarly,when i use the "soartex fanver"texturepack and change the texturepack into defualt,it will also happened.

I don't think this bug is Buildcraft specific, I ran into the same bug with Railcraft Iron/Steel Tanks.

so you mean...does this bug belong to forge liquid system?

@asiekierka are you rebuilding display lists on TextureStitchEvent.Post, this event signals that UV positions in Icons could have changed.

@BoyHarry No, this seems to be a bug in Minecraft. This also sometimes happens for blocks that have different textures for different sides.