I have heard of this too.  Exactly what part needs to be replaced?

If this is a known issue, then the people who it hasn't happened to yet, should replace the soon to be broken part.

Yes, it is absolutely unbelievable the number of homes this has happened too.  Our cousin that lives in here had it happen in her master bath on the second floor.  They were out of their house for 3 months and the insurance bill was outrageous.  Weeks later one of my rental listings on Pioneer had it happen, I was lucky to find it hours after it happened, and only flooring had to be replaced.  That same day at lunch my husband luckily was home and our downstairs toilet popped.  He was able to shut off the water and run to Maricopa Mountain plumbing to replace ALL of our toilets.   In September of last year, my husband discovered the neighbors house flooding out the garage and front door, we shut the water off to the house and had them called home from vacation.  That entire home was flooded up pass the baseboards.  I noticed a home on Gibson within the last couple of weeks that is torn down to the frame from half the wall down and the other day the water restoration company was there. 

Mansfield should have corrected this a long time ago.  The most frustrating part is that a lot of these people are walking away from their homes and letting them go to foreclosure. 

Just moved in last week and replaced our 3. Went to Ace, they also have replacements.

Here's my question.  If the faulty valve is inside the toilet tank, why won't the lid of the tank contain the water so that it goes down the overflow pipe instead of flooding the house?   I thought that was the reason the lids were made heavy with the bottom of the lid contoured to fit the tank.   

The breakage occurs at the threaded end of that part. It is outside the tank, where the supply line from the wall meets the tank. When it broke in my house I was there and within a few minutes the paint was 'pressure washed' off the wall.

Thanks for clearing that up, pkat.  I was under the inpression that the defect was in the float valve at the top of that threaded stand pipe, which is inside the tank.  I have Mansfield toilets, but the connector tubing is very flexible, so there shouldn't be any stress on that part.  

I'll change them out anyway.  I don't like the kind of float valve they have anyway.  I've always used the type that has the float encircling the stand pipe, as replacements.

I contacted Mansfield and they sent me the replacement  parts free of charge. Contact Kay Whitcomb 419-994-6376 or 877-850-3060 ext.-6376 or KWwhitcomb@mansfieldplumbing.com   Makes you think they aware of the problem.