Something very strange happening in my laundry room

[spinspeed]

Ok guys, I have a Maytag Atlantis washer and an old Simpson TL washer that share the same cold water supply with a Y adapter. Today when the Maytag was filling, water started to trickle in to the Simpson washer, even though it was not switched on. When I switched the Maytag off so it stopped filling, the tricke stopped in the Simpson. On switching the Maytag on again allowing it to continue to fill, again water started to trickle in to the Simpson. Really strange. Does anyone have any ideas what could be causing this?

Cheers
Simon

 

[arbilab]

IINM, these valves use the line pressure against a diaphragm to seal them closed. When the 'Tag is filling the line pressure goes down.

 

[DADoES]

 
Yes, water pressure is what makes the valve seal, so a substantial drop in pressure can cause dribbling.