I just had another thought but no sure how or where to pull it off. On boats we go to a pump-out station. There is a large diaphragm pump that creates a vacuum and pulls the waste out.
Here is a link to a product that I discussed last year during a previous discussion, the Sewer Solution;
http://www.sewersolution.com/
This is a cap that would attach to the discharge fitting although you may also need an adapter. The cap has a water hose fitting and the jet spray is able to go into the tank or help discharge the waste. I would really think hard about this product to help with you dilemma and it would be much less than paying a shop to work on it, if it didn't work at least it would be a piece of gear. The people that purchase this at the RV park that we were at swore by it.
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have Coach will Travel
Steve & Tricia
1982 Newell 38' (built before #1) 6V92 DD, 5 Speed Allison, 12.5 KW Kohler, Couch used to make into a Bed but I fixed it!
https://newellshowcase.com/thumbnails.php?album=214
2007 Yukon, 1981 CJ7 Laredo, 2002 Honda CRV, 1955 Thunderbird, 1952 Pontiac Sedan Delivery, 1952 Ford 8N, 1958 Airstream, 1959 Glasspar 16' Avalon, Cabin in the Woods........what will I work on next
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