Kohler10351-NA Universal Rite-Temp Test Cap for K-8300 Series Valve Bodies

used it in my remodeling project, this allowed me to test my soldering in stages. I probably did not need it but it was trivial in price compared to everything else I spent on the project

A must have for pressure testing your final build out and flushing of lines. The real question is, why wouldn’t this come with the overpriced shower valve?

Installed this test cap to verify new plumbing was leak free. Instead found this test cap itself was leaking, even when tightened as much as physically possible onto our Rite Temp valve housing. In that state it would have about one drop of water escape every few minutes or so. Eventually after a few hours of supervising other plumbing joints, I decided to install the actual shower cartridge itself to see whether the leak would persist. On closer inspection, I noticed the final Rite Temp cartridge has a gasket that goes around the entire circumference of the cartridge - the test cap has a groove that one would think is for this same gasket, however there was no gasket present on the test cap. A plastic to brass connection with no gasket seems destined to leak - I can't find any pictures of the back of this test cap online, so don't know if it is a bad design or bad quality control.Giving an extra star because the water leak was slow enough to maintain water pressure and identify another leak that needed to be fixed elsewhere, but very disappointed. A waste of $7 since we had to install the shower cartridge and turn it on to test everything!