On Wednesday, May 11, 2016 at 4:46:53 PM UTC-5, Taxed and Spent wrote:
1980s vintage Maytag washing machine, not much use given the age.

On the fill cycle, water on the floor.

The hose seem ok, but there is some sort of an air gap in line between
the solenoid valve and the tub. What is this gizmo and how is it
supposed to work? What are its failure modes?

It serves an anti-siphon function to prevent wash water from getting into the potable water supply if the is a sudden pressure drop. It's function is like that of the backflow preventer gismo on your outside faucet to keep water in the hose from getting into the water supply. It possible that the rubber has degraded or there is debris in the line. ^_^

[8~{} Uncle Hoser Monster