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