We recently upgraded our black/gray drains system to incorporate LHC's fast gray drain.
The kit does NOT include a black tank T valve. We figured that, as long as we're replacing the rest of the system, why not put in a new black tank T valve as well. We purchased a new black tank T valve from an RV store and installed it as part of the whole upgrade process.
It leaks. We discovered that BEFORE we used it, using water. The instructions for installation are scant at best, are virtually useless. I believe it advises to NOT tighten the four mounting bolts too tightly.
I'm not sure why it's leaking. It's brand new. I think I remember seeing that there was a gap between the side of the 'curtain' and the housing, but...that may just be my imagination, and we've not dismounted it to see why it's leaking. Yet.
The question arises in my mind...given that the T valves are subject to drying out, and sometimes failing altogether; the stem sometimes pulling out completely; sometimes the O rings getting buggered up or an installer not getting it exactly smuck on in the so called 'groove' for the O ring, which I have found is virtually non-existent, etc, why are they used AT ALL?
Why not use a simple ball valve?
Is there some reason why this particular system that seems to be susceptible to problems is the preferred installation for RV's/trailers, etc???