Haunted plumbing here, help !

[mike honkoski]

There are three bathrooms with showers in this house, all of the shower heads, pipes and hot / cold adjustment valves are new and i even have a new and properly working pressure regulator.
Now then none of the showers leak or drip any water and they all work perfectly.......Untill i turn on any one of the showers, then all the others start dripping water, a lot of water, not just drip drip drip.

 

[Terry]

What brand and model of valves do you have?

 

[Sponsor]

 

[mike honkoski]

What brand and model of valves do you have?

Thank you for your reply, really seriously thank you. I have no clue so I am going to take them apart tomorrow and look for a brand mark and etc, the only thing i know right now is that they are all of very similar design and that the mixxer valves themselves inside the things are fiberglass or plastic