DaveC wrote:

Yes, that is the part that is causing the leak.

Or it was on mine when I replaced it.

I was told that it was a method of aerating the water so that it would
"spray" into the tub, which during rinse cycle is important.

No Bill is correct !

"If the water pressure drops to zero while filling the tub, dirty water
could get drawn back into the city water main."

That is exactly what I was going to say... Bill beat me to saying
it. ;-)

The action of the tub aerates the water.

--
Best Regards:
Baron.