@VigII posted:Why would you blame the borax/Dawn treatment? Did you do further rinces until the rinse water ran clear? You shouldn't store the trailer with empty tanks. Alway add a few gallons of water to prevent the knife gate seals from drying completely. Did you follow the full procedure?
Sounds to me that the 1 treatment loosened stuff. Watch the video I linked above.
I did rinse the tanks a couple of times after I dumped the Dawn and borax solution. I did add water and Happy Camper before I stored it. The treatment seemed to remove the lubricity from the seals. Even after several dumps and flushes over the next couple of weeks, it was still difficult to get the valves open and closed. I have never had this problem before I did the treatment.
I was going to replace both valves if the mod I made to the valves didn't work. Valve replacement would have been very difficult in the very small dump compartment.