I couldn't find a leak on mine. I found it easier by taking it out and sitting on top of a table with two 2x4 under toilet hooked it up to water and electric flushed away and found my problem.
Prior to bringing it outside
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU