How I fixed my cycling Vacu flush

[Quint4]

Vacu-flush fun! Vacu-flush was cycling every 3 minutes. The bowl was holding water but it was losing vacuum somewhere, hence the cycling pump. I threw some parts at it and finally hit on the right one. I replaced all 4 duck bill valves, ball gasket, & the water valve at the toilet (it had a small dripping leak). The pump still cycled....darn it.

I then ordered a "Ball shaft cartridge kit". I had read the seals on the shaft can be the culprit. This is the shaft that rotates the ball when you step on the foot lever. Bingo....problem solved! No more pump cycling.

I will say the kit I ordered claimed to fit my 20 year old 806 model head, but the ball did not fit (I re-used the old ball). The other parts fit to include the shaft. Just wanted to share as I know Vacu flush systems can sometimes be a source of trouble.

 

[juggernaut1]

Same thing fixed mine from cycling too after replacing the duckbill valves didn't. The ball in the kit fitted my setup.

 

[bbwhitejr]

Rebuilt one of my Vacuflushs and still cycles on/off. I will try this. Thanks!
Bennett

 

[redlightning]

You can also purchase the entire toilet base assembled. Its an easy swap out. just a bit more cost.

 

[copb8tx]

Also check the 2" (might be 2.5") gasket that drops the waste from the vacuum generator into the tank. On mine there was a 90 degree elbow that went into the tank. I'd done the duck valves, bowl ball seals etc. but in the end that simple seal fixed the issue.

 

[boatrboy]

So did your cycling intervals start out longer? Mine seems to cycle once after putting battery switches on.
I first noticed every hour or so it would cycle while I was prepping the boat for the year. I wiped the bowl seal a few weeks back and it seems to get better. Now when I go to work on the boat the pump runs but only once. Is this how yours started?

 

[Quint4]

New to me boat. Cycling was every 3 minutes prior to my fix.

 

[The Bill Collector]

I let NoFlex Digester sit in the lines all winter and in the spring no more cycling...

 

[Alum of CU]

I had a leak in one of mine (real nasty due to clamp fail) but ended up doing both pumps. I took them out, soaked in sew clean, put back together with same parts. All duckbills replaced, but yes, there was an additional one coming off the captains head. So I just picked the best of the 5 that I had and reused it. Both systems solid now and will come back to the boat a couple of days later and they are still good. Before they would cycle every 10 minutes or so.
Edit: Good job everyone on the vacuflushes btw.

 

[mobocracy]

I've had problems with minor leaks in the tail pipe fitting that connects the septic line to the vacuum accumulator. Pump wouldn't stop cycling or hold a vacuum. Tightening them up almost imperceptibly solved it.

I also broke down and bought a vacuum gauge/tester so I can see how much vacuum the pump itself generates and how well it holds vacuum. This lets me see if the duckbills and vacuum pump side is OK vs. the head ball valve, or worse, some kind of permeation on the septic hose from the head to the vacuum pump.

The latter is might nightmare because replacing the hose from the head to the vacuum pump looks like a total nightmare job.

 

[Little Ducky]

I then ordered a "Ball shaft cartridge kit". I had read the seals on the shaft can be the culprit. This is the shaft that rotates the ball when you step on the foot lever. Bingo....problem solved! Not more pump cycling.

View attachment 104294

Are the "O" rings replaceable by themselves or when it's time to replace.... the mechanism is past it's prime and easer to replace the entire piece?

 

[Alum of CU]

I've had problems with minor leaks in the tail pipe fitting that connects the septic line to the vacuum accumulator. Pump wouldn't stop cycling or hold a vacuum. Tightening them up almost imperceptibly solved it.

I also broke down and bought a vacuum gauge/tester so I can see how much vacuum the pump itself generates and how well it holds vacuum. This lets me see if the duckbills and vacuum pump side is OK vs. the head ball valve, or worse, some kind of permeation on the septic hose from the head to the vacuum pump.

The latter is might nightmare because replacing the hose from the head to the vacuum pump looks like a total nightmare job.

I had to cut an access panel in my crew head to fix that pump and hose fittings there was no other way to get to it. removed tile, cut access, retiled with updated look.

 

[Quint4]

Are the "O" rings replaceable by themselves or when it's time to replace.... the mechanism is past it's prime and easer to replace the entire piece?

Not sure if the "o" rings are available...perhaps. The new shaft is brass as opposed to plastic so its better to replace it all in my opinion.

 

[Alum of CU]

Vacu-flush fun! Vacu-flush was cycling every 3 minutes. The bowl was holding water but it was losing vacuum somewhere, hence the cycling pump. I threw some parts at it and finally hit on the right one. I replaced all 4 duck bill valves, ball gasket, & the water valve at the toilet (it had a small dripping leak). The pump still cycled....darn it.

I then ordered a "Ball shaft cartridge kit". I had read the seals on the shaft can be the culprit. This is the shaft that rotates the ball when you step on the foot lever. Bingo....problem solved! Not more pump cycling.

I will say the kit I ordered claimed to fit my 20 year old 806 model head, but the ball did not fit (I re-used the old ball). The other parts fit to include the shaft. Just wanted to share as I know Vacu flush systems can sometimes be a source of trouble.

View attachment 104294

Also, for those of you watching this thread, don't ever disassemble that sprint cartridge. Mine was an older model and while I got it back together, it was quite difficult.

 

[Irie308]

Are the "O" rings replaceable by themselves or when it's time to replace.... the mechanism is past it's prime and easer to replace the entire piece?

Had to do this once on our 320 and I was able to get the O rings from Home depot. Worked like a champ.

 

[mobocracy]

I had to cut an access panel in my crew head to fix that pump and hose fittings there was no other way to get to it. removed tile, cut access, retiled with updated look.

The sanitation from the hose on my 310DA goes into a sealed opening and into some kind of bulkhead space under the septic tank. I don't think its even visible again until you go into the aft cabin and start pulling up cushions and/or access panels. The entrance to the hose path is rear-facing and real tough to reach without lying on the port engine. I also worry that the hose is clamped or tie-wrapped inside the bulkhead.

It looks hard enough to deal with that I would seriously consider a redneck solution like trying to re-line the septic hose with EPDM roof sealant in a manner similar to the way that utility water mains get re-lined -- attach two sponges to a pull line, pull one in, pour in liquid EPDM, pull in second sponge, let it cure, and keep repeating until the septic hose has a new internal lining. It might work.

 

[Quint4]

The sanitation from the hose on my 310DA goes into a sealed opening and into some kind of bulkhead space under the septic tank. I don't think its even visible again until you go into the aft cabin and start pulling up cushions and/or access panels. The entrance to the hose path is rear-facing and real tough to reach without lying on the port engine. I also worry that the hose is clamped or tie-wrapped inside the bulkhead.

It looks hard enough to deal with that I would seriously consider a redneck solution like trying to re-line the septic hose with EPDM roof sealant in a manner similar to the way that utility water mains get re-lined -- attach two sponges to a pull line, pull one in, pour in liquid EPDM, pull in second sponge, let it cure, and keep repeating until the septic hose has a new internal lining. It might work.

I am wrapping any sections of exposed waste lines with Gorilla waterproof tape for hopefully a temporary fix to a slight odor. I would guess they are permeated and need replaced but I'm not up to the full job just yet.