TL;DR
Allow fluid wagons to work when part of the train is on a curved rail by changing the pump arm graphic.What ?
viewtopic.php?p=500666#p500666The way it is now looks dang pretty, but pumps wont connect to fluid wagons when part of the train is on a curved rail due to a precise alignment requirement of the pump arm graphic.
As boskid says in the bug forum, the best solution would be to change the graphic of the pump arm, so that it has a higher alignment tolerance.