Chris-380
Well-Known Member
When mine still leaked, I changed the bellow and that did it
Vacuflush system won't hold pressure
- Thread starter drprunner
- Start date
Dont mean to hijack the thread, but any insight into this….
Hoping to get a little help. Whole system still seems to work fine BUT am having pressure pushed up and leaking through the saver vent and the tank level cap. Anyone ever seen these happen simultaneously?? When system builds up pressure, pump turns off but it pushes contents up through just these two locations. After a while the pump will turn back on to again build pressure etc. is it hopefully as simple as replacing these to parts or any other ideas?? Filter replaced every year snd duckbills every two. But this just started
Hoping to get a little help. Whole system still seems to work fine BUT am having pressure pushed up and leaking through the saver vent and the tank level cap. Anyone ever seen these happen simultaneously?? When system builds up pressure, pump turns off but it pushes contents up through just these two locations. After a while the pump will turn back on to again build pressure etc. is it hopefully as simple as replacing these to parts or any other ideas?? Filter replaced every year snd duckbills every two. But this just started
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techmitch
Well-Known Member
- May 1, 2008
- 8,394
- Boat Info
- 1999 270 DA
- Engines
- Twin 4.3s W/Alpa I Gen II's
Was a plunger ever used?
Not since ive owned it goin on 6 years
its in a 2004 320…. I did notice several weeks ago the pump ran longer than normal. Just let system set thinking maybe something in a duckbill. Came back few days later and all was perfect for several weeks now snd just discovered this today. No plunger or anything with exception of pump outs regularly every two weeks
techmitch
Well-Known Member
- May 1, 2008
- 8,394
- Boat Info
- 1999 270 DA
- Engines
- Twin 4.3s W/Alpa I Gen II's
Make absolutely sure the vent is clear from the outlet of the tank through the filter to the outlet on the boat.
It appears to be. Unhooked filter and appears good flow and no blockages either way. Have not replaced this filter yet this year but was new in Aug. guess its possible its blocked some. Any chance a leaking duckbill could allow pressure to build in the tank??? Just not sure why pump builds good pressure then kicks off as normal if thats true. I am so at a loss with this
Jaybeaux
Well-Known Member
- Jan 3, 2016
- 2,053
- Boat Info
- 2006 Sea Ray 48
Naught On Call
- Engines
- Cummins QSC-540s with V-Drives
11 KW Onan Genset
The holding tank is vented to the atmosphere, via the "fart filter" and the vent on the side of the hull. The only way the holding tank can pressurize is if there is a restriction in the vent line. Remember the vacuum generator is under vacuum. Hence, atmospheric pressure is high relative to it. The sources of the "high" pressure are:
1. The bowl seal
2. The duckbills
3. The bellows (it can crack and is between the two sets of duckbills)
4. The O-ring seating the bellows pump.
5. Cracked lines normally under vacuum
6. Poor connections where the lines under vacuum enter the vacuum generator.
Jaybeaux
Chris-380
Well-Known Member
If I am guessing the vent is clogged, through the filter or hose….
drprunner
Member
Anybody know the Sealand toilet model # for a 1997 400 Sundancer? I'm trying to buy the gasket for the toilet, but can't find the model #.
Korkie
Active Member
- Feb 2, 2016
- 1,331
- Boat Info
- 2006 340 Sundancer, Garmin 7610, xHD 24 Radar, VV703, SeaStar Hydraulic Steer, Shadow Drive AP
- Engines
- Mercruiser 496 Mags
Bravo III Drives
Easy step to isolate problem. Disconnect the hose coming from the toilet that connects to the Vacuflush system. Block off the intake to the Vacuflush (I use a tupperware cup that happens to fit like a cork). Turn on the system, if it creates a vacuum and shuts off, it is not that unit. Problem is between blocked off intake and toilet bowl. If it creates vacuum and does not shut off, it is the limit switch.
Easy step to isolate problem. Disconnect the hose coming from the toilet that connects to the Vacuflush system. Block off the intake to the Vacuflush (I use a tupperware cup that happens to fit like a cork). Turn on the system, if it creates a vacuum and shuts off, it is not that unit. Problem is between blocked off intake and toilet bowl. If it creates vacuum and does not shut off, it is the limit switch. This will take 50% of your system out of the equation.
Well it's not the duckbills
Replaced the 4 duckbills and re-installed the vacu-flush. Nothing's changed, bowl holds water, and pump cycles but never shuts off. I'm getting a vacuum at the bowl, when I flush it I can hear the vacuum/suction.
Any ideas??
Easy step to isolate problem. Disconnect the hose coming from the toilet that connects to the Vacuflush system. Block off the intake to the Vacuflush (I use a tupperware cup that happens to fit like a cork). Turn on the system, if it creates a vacuum and shuts off, it is not that unit. Problem is between blocked off intake and toilet bowl. If it creates vacuum and does not shut off, it is the limit switch. This will take 50% of your system out of the equation.
Help identifying what model my tank is. Still trouble shooting my issues but the model number is unreadable. Serial number is HTS2815967. Emailed Dometic but they said they didnt have that info. Any help so I order correct parts would he very appreciated
Attachments
Take the base of the head apart, The number you need are at the base of the head
my problem last summer was the hose cracked where it makes a hard bend right before the pump
- Jul 11, 2012
- 885
- Boat Info
- 2000 ~ 510 Sundancer
2024 ~ Highfield 360 Sport
Twin Axiom 12" MFD's
AIS 700
- Engines
- Twin Cat 3196's
I helped my buddy fix his system last year. We replaced everything and it still wouldn't hold vacuum.
While I was tucked into his bilge and he flushed a copious amount of water into the line I found the problem! His hose to the tank was very "checked" and for a brief moment I saw water seep out between the cracks, then get sucked back in as it tried to generate vacuum. We were a little surprised since this is a 2008, 48 Sundancer. I didn't think the lines could go that bad in that short amount of years and being in Michigan, it gets used little due to the short season.
We cut a section of hose out, inserted a barbed coupler and added a new section of line for a temporary summer fix. This winter he had the lines replaced from the head to the pump for both systems. I did teh same thing on my 460 a few years back and it solved a multitude of issues, most notably the odor was gone from the hoses seeping a foul stench. Luckily my new to me 510 had the hoses all replaced by the PO before we bought it.
While I was tucked into his bilge and he flushed a copious amount of water into the line I found the problem! His hose to the tank was very "checked" and for a brief moment I saw water seep out between the cracks, then get sucked back in as it tried to generate vacuum. We were a little surprised since this is a 2008, 48 Sundancer. I didn't think the lines could go that bad in that short amount of years and being in Michigan, it gets used little due to the short season.
We cut a section of hose out, inserted a barbed coupler and added a new section of line for a temporary summer fix. This winter he had the lines replaced from the head to the pump for both systems. I did teh same thing on my 460 a few years back and it solved a multitude of issues, most notably the odor was gone from the hoses seeping a foul stench. Luckily my new to me 510 had the hoses all replaced by the PO before we bought it.
drprunner
Member
Today I finally fixed the problem (original topic of this thread). It was the o-ring on the pressure switch.
- Apr 10, 2021
- 997
- Boat Info
- 1999 Sea Ray 290 DA
- Engines
- Twin 4.3 with Alpha 1 Gen 2 drives
Thanks for letting us know!
Jon
SeaNile
Well-Known Member
As of last weekend I am now having this same issue. Both bowls hold water but every 5-10 min the pump comes on for about 10 seconds then shuts off. Was doing this for a few hours today so I just turned everything off for now. Add that to my spring to-do list. Oh, and troubleshoot why the macerator pump runs but will not pump out. I was curious if it worked since i never used it before. Flushed with water till 1/2 tank and then found out it doesn't pump out. So now here I am 1/2 full and the pump out station is still winterized. Brilliant move on my part.
