Strange Vacuflush problem

[3birds]

Went to drain the holding tank. Hooked up the hose and turned on the pump. Nothing coming up the hose. Stuck a garden hose down the deck fitting and turned on the water and the waste started coming out the vent. Went inside and flushed the toilet. This also pushed the waste out the vent. If holding tank is empty, where is the waste and what is causing it to push out the vent? The entire tank system is very difficult to access.

 

[PascalG]

not a VF issue but a pump out problem.
if waste comes out the vent when you flush, the head is workign fine but your tank is full.

if nothing gets pumped out, either the suction is too weak or you have an air leak in the hose, fitting or in the hose between teh deck fitting and the tank.

if you see stuff coming out the vent, that means you don't have a vent filter, so you can eliminate that and focus on a leak in the pump out hose

 

[HOGAN]

Probably a clogged vent. Try spraying water into it to clear it.

 

[3birds]

That makes me feel better. I'll take the boat to a different pump out station. There is a bunch of duct tape wrapped around the hose at the station I used to that could be the culprit.
I did try shooting water into the vent thinking the same thing. I didn't work. I wouldn't think it is clogged if I am getting flow from the tank side, unless there is some time of check valve or ball in the line.

 

[PascalG]

no check valve in vents... if it was a clogged vent nothing would come out when the tnak is full and you'd be pressurizing it when flushing.

 

[Capt. Bill1]

I wouldn't recommend using that hose to fill your water tanks till you disinfect it real well.