Recently the water-main in my neighborhood was replaced. I think sediment got into our pipes and have damaged the diaphragms in our toilets. What we have are DELANY REX VALVES Same as; simply search this page for "Rex" and you'll find the diagram. http://crestgood.com/catalog/Ch 08 complete.pdf The issue: Two of our toilets continuously flush (water runs) when the lever is pulled. I've turned off the screw valves on the fixtures (these are tankless rex valves if you've seen the diagram). I've read all I need to do is replace the diaphragm, Simply getting a repair kit from the hardware store etc. My question to you guys: Is this all I need to do, and how is this done properly? Detailed is what I'm looking for, detailed enough as to even where the brass pinhole part should be, adjacent to the lever, exactly where? Any, any help at all would be awesome! Also I'm not quite sure how to know what gallon type I need to get, I remember 3.5 from the last plumber that came in to repair but unsure. How would I be able to gauge that? THANK YOU THANK YOU THANK YOU!!!