Click for Mulder Click for YF Listing Service Click for Furuno Click for Burger Click for Glendinning

Vacu Flush Issue

Discussion in 'Technical Discussion' started by CSkipR, May 2, 2020.

You need to be registered and signed in to view this content.
  1. CSkipR

    CSkipR Member

    Joined:
    Aug 16, 2008
    Messages:
    965
    Location:
    New Smyrna Beach, Fl
    I just changed the 4 duckbills and while I was at it decided to replace the old bellows as its 15 yrs old. Put back together, pressed floor pedal to let some water in the bowl (water pump was not on). Turned the head breaker and water pump on and vac motor is running but not getting any vacuum. Lifted the pedal to release more water in bowl and it is full. Appears no vacuum and I can see some water around the top of the bellows.
    Puzzled as to why its not working.
  2. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale

    You either have a duct bill in the wrong direction or an air leak at the bellows where it's not building pressure.
  3. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,647
    Location:
    Satsuma, FL
    Holler when you need a third hand. Were in Satsuma now (lil closer) with a case of cabin fever.
    I'll even work on your head to get on the road again.
  4. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,118
    Location:
    Miami, FL
    Yep. Either a duckbill the wrong way or an air leak on the pump body. VF use screws into a plastic body. With age the plastic gets stripped and the screws don’t hold enough pressure. If that’s the case replace the screws with nuts n bolts

    Also when installing duckbills I always put liquid soap on the flanges so they don’t get distorded when tightened up
  5. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,647
    Location:
    Satsuma, FL
    Hand snug only...
  6. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    You know what just happened to me on a vaccuflush around your age.....I changed the entire pump and the 90 pvc fitting on the bottom of the toilet became loose and that's where the air leak was, so resealed it.
  7. T.T.

    T.T. Senior Member

    Joined:
    Jan 22, 2010
    Messages:
    92
    Location:
    S.F.
    foam shaving cream is helpful to find the pesky leaks
  8. CSkipR

    CSkipR Member

    Joined:
    Aug 16, 2008
    Messages:
    965
    Location:
    New Smyrna Beach, Fl
    Duckbills were all in correct I've installed them before. It was the bellows that was the issue. I did not preseal the bellow against the underside of the bellow casing before installation. Once I did that and reinstalled bellow for the third time it worked perfectly.
  9. chesapeake46

    chesapeake46 Senior Member

    Joined:
    Jul 26, 2009
    Messages:
    1,776
    Location:
    Chesapeake Bay, Delaware Bay & S.Jersey
    You're a good man, Charlie Brown.
  10. offshore1

    offshore1 New Member

    Joined:
    Jul 29, 2012
    Messages:
    26
    Location:
    no
    Never heard about presealing the bellows.
    How is that done and with what ?
  11. Alzira II

    Alzira II Member

    Joined:
    Jan 22, 2019
    Messages:
    159
    Location:
    Fort Lauderdale
    I bought a pressure tester with a rubber cone shaped end that you can stick into the pump or any line and isolate the system and check it. I must admit I have not used it yet but it’s great peace of mind so that when the vacuum flush does act up it makes it a lot easier for me to figure out where the leak is coming from. Nice tool for anyone who has vacuflush on board.
  12. Alzira II

    Alzira II Member

    Joined:
    Jan 22, 2019
    Messages:
    159
    Location:
    Fort Lauderdale
    Vacuum test not pressure
  13. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,118
    Location:
    Miami, FL
    You easily judge the vacuum level by applying pressure on the vac switch spring. The harder it is to pull the rod for the switch to turn off the pump the less vacuum you have. If all it takes to trigger the switch off is a light touch you know you almost have enough vacuum. 20+ years with VF and without the Sealand priced vac tool

    in the end it doesn’t matter. If the pump doesn’t shut off the tool won’t tell you why. 99% it’s going to be the duckbills. 1% it will be the vac switch. Unless you have a very obvious leak at the ball valve aeal
  14. CSkipR

    CSkipR Member

    Joined:
    Aug 16, 2008
    Messages:
    965
    Location:
    New Smyrna Beach, Fl
    When u replace the bellows u need to press it to the underside of the top piece (it will actually suck onto that piece) that the motor mounts on and then attach the two lock pieces around the bellows.