Hep2o pushfit grey, Grab Ring Failure ?

[Chuck]

I had a leak coming out from this reducing tee just after a month after installation.

You'll be wanting to replace/rework every joint made as part of that installation then. If one is like this, it's a sure thing that there will be others

 

[Ric2013]

I must say I've taken apart fittings that old (under a caravan that was going to be scrapped and needed zero-budget work done), bent the metal grab rings to about the right shap, and reassembled using modern Hep pipe and it held (at around 5 bar) until the caravan was scrapped a year later. (No, this wasn't a paid job, in case you're wondering.)