Thought I would add an update of what happened.
I called 2 mobile RV guys. No one got back to me so started doing as much research as I could on the Internet.
Looked like 2 options... One that the pipes coming from the tub and sink where a slip fitting.. In theory unbolt tank and slide down to see if something was broken.
Option 2... Pipes coming into tank where either glued in or screwed on.
So, after lots of discussion with SO we decided on (Labor Day Weekend) to dig in.
After disconnecting all the sensors, dump valves, cross member holding the grey tank, we were able to drop it down. However just a couple of inches...
After pushing my head against the bottom of the sealed underbelly I could see that the drain tubes from tub and sink were not slip fittings...
So into the rig we go. No room under tub to work so had to pull the bath tub. Really not as hard as I thought, also pulled everything up from under the sink cabinet. Amazing how much stuff SO can stuff up in there.
Had to cut the vent pipes and tub drain pipes to let the grey tank down. Got it down and started to do inspection.
Had to cut a bit of underbelly sealed insulation because it was soaked. After laying on the ground for a bit notices a drip coming from the hot water line of bathroom sink. Followed it up, and can you believe the hot water pex fitting was not tight on the sink faucet which led to a little leak. It was just enough to go down the line into the underbelly slowly over time drenching underbelly insulation. the insulation just could not absorb anymore so started showing on ground.
This is a 10 year old trailer new to us and the first time hooked up full time to water. figure over the last month about 30 gallons of water.
All I had to do to fix was unscrew the hot water line form the sink faucet and reinstall.. It had been cross threaded...
Now to put it all back together. After Several Home Depot trips we got it all back together and all in.
Took us about 15 hours over the 2 days. This included new insulation, plastic underbelly tarp, re-installing grey tank, new abs drain pipes (remember had to cut all the ones to get tank out) and a PEX fix because I stapled a hole when re-installing insulation.
Lesson Learned. It's a lot of work, but doable. Lots of time on your back beneath the rig. Watch where you staple, and be sure to have some cold ones on ice.
I couldn't find a lot of info on doing this, and didn't take any pics PM me if you have any questions.