05-15-2022, 12:24 PM
I have just encountered the same issue on my 2007 4300 Sovran. Forward head pump cycles approximately every 3 minutes. Toilet bowl holds water. Replaced duck bill valves and no change in cycling time. Local vacu-flush tech suggested changing out black water plumbing lines. I have examined Tiara schematics and cannot find any designed access points to assess feasibility of a DIY job. Have you fixed your issue?

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