Vacu Flush not Flushing

[md2020]

Had and issue over weekend where pedal on toilet got stuck in down position, guest did not notice when they were done and left it down, after using all the fresh water in the tank the vacuum pump kept on pumping. Not sure how long this went on for, figuring maybe a half hour before I noticed. Now the pump just keeps pumping when pedal is depressed but will not clear out bowl. It's a J series vacuum tank. Holding tank has been emptied. Any thoughts or ideas as to where to go from here would be greatly appreciated.

[sabray]

Could be a clog. Guests are great for that. Try putting a wet dry vac on the tank vent line while running the pump and flush. I have had good luck clearing a jamb with my vac u flush this way.

[sailvayu]

If you over filled the holding tank it is possible the duck bill valves in the pump were damaged. This is where i would start looking. You can check theses by taking the hose off the pump fittings and unscrewing the hose barbs. Keep in mind on one side at least the barbs use a left hand thread so do not force them. The duck bills will be inside these barbs. Not a pleasant job but not too hard either. If it is not this the pump itself could be damaged or as mentioned a clog. Good luck

[md2020]

Thanks for your ideas, will try both. One puzzling thing that I cannot get my head to grasp is where did all the fresh water from my 50 gallon tank go..It was at least half full and waste tank is 18 gallons. Out vent line???? If so vent filter is done....

[sailvayu]

It is possible it pushed the water through the discharge pump and out the thru hull if it was open. I would be surprised if that much went through the vent but it could happen. Either way I am guessing you are going to have to replace the filter as surely some waste got into it.