Guaranteed way to have a vacuum leak at the pump top/bellows O ring seal. The leak he had was from that seal. The tank seal NEVER leaks unless it is disturbed by disassembly. Also, when reinstalling the hose fittings, you tighten by hand until they stop, then 1/4 turn. Any more than that and you risk stripping either the nut or the tank. This is a perfect video of how to cause more problems than you fix. I've been a service tech and dealer for VacuFlush for over 20 years.
No sound, which helps if the narrator doesn't talk too much!! Still a good video. I had the same exact setup and I never would have located the two duckbill valves in the under the pump. Thanks for making the video. THis unit takes the 2 inch duckbill valves..
I have a slightly different configuration and pump model, but it is a Dometic. I have tried a rebuild kit and keep getting water building up in the bellows chamber, which slowly fills and over flows outside of the unit. Any suggestions on what I am missing ? Thanks for any tips!
The only way to have water building up in the bellows chamber from the design I have is a leak from the inner o'ring (at 6:54 in the video) or the bellow itself, not sure about yours. Maybe the o'ring sealing surface on the cover is damage? or the o'ring itself was damaged on the installation (sometime this happen). Since you used a rebuilt kit I would assume the bellow was good but you never know, is there a small crack on it?
The only other vacuum issue I had with the vacuum unit (excluding the toilet) since this maintenance was done was with the vacuum switch. The symptom is the unit will run non stop or it will run and quickly loose its vacuum and restart again because the vacuum switch membrane is cracked and the air come through it. The easy way to find out is to remove the switch, clean the membrane on the switch and inspect it carefully.
@@svkiara1040 thank you, we've found that the inlet side was at fault, the generator itself was pulling a vacuum. Jubilee clips now tightened and all working :-)
As you can see at 6:15 in the video, my bellow is also not tight in the cylinder. This is not critical since the way this bellow works when it is pulled up is by changing the volume in the cylinder chamber by the volume it is compressed which create the suction in the inlet pipe as long as there is no leak from any other joint. What maintain the vacuum in this chamber (cylinder) are the 2 o'ring seals you see at 5:39 and 5:41 and also the duck bills from the outgoing pipe and the o'ring seal between the cylinder and the tank as shown at 2:40. As long as the bellow clamps (half rings black at 6:04) are tight to hold it in place this should be ok.
Thank you for this EXCELLENT video on disassembly and rebuilding the Dometic VG4 Vacuum Generator.
Real good show of how this work should be carried out thank you
Guaranteed way to have a vacuum leak at the pump top/bellows O ring seal. The leak he had was from that seal. The tank seal NEVER leaks unless it is disturbed by disassembly. Also, when reinstalling the hose fittings, you tighten by hand until they stop, then 1/4 turn. Any more than that and you risk stripping either the nut or the tank. This is a perfect video of how to cause more problems than you fix.
I've been a service tech and dealer for VacuFlush for over 20 years.
6:06 😊
Excellent how to video. Clear concise and correct. Thanks!
No sound, which helps if the narrator doesn't talk too much!! Still a good video. I had the same exact setup and I never would have located the two duckbill valves in the under the pump. Thanks for making the video. THis unit takes the 2 inch duckbill valves..
Wow! Best how vacuflush service video. Thank you
Thanks!
Thanks for posting this. Pretty close to my set up. This is going to be a HUGE help.. Thanks again..
Thanks. The boat maintenance yard says they only install new ones, rebuild is up to me. This will really help.
Thank you, our billow just cracked. yuck, urine in the bilge. at 5:16 in your video was very helpful.
Best video I’ve used as my guide it still did it work until I ran a bead of silicone around the outside o the two tank seam half ..,Frank
Awesome, thanks. I was wondering where those last 2 duckbill valves went!
Nice explanation. About to do the same job. Thanks
This was a huge help, but for gosh's sake clean the tank before your install O rings!
Excellent video and information! I assume no sound is it's impossible to talk while smelling the smells you smelt? Thx!
Great video
I have a slightly different configuration and pump model, but it is a Dometic. I have tried a rebuild kit and keep getting water building up in the bellows chamber, which slowly fills and over flows outside of the unit. Any suggestions on what I am missing ? Thanks for any tips!
The only way to have water building up in the bellows chamber from the design I have is a leak from the inner o'ring (at 6:54 in the video) or the bellow itself, not sure about yours. Maybe the o'ring sealing surface on the cover is damage? or the o'ring itself was damaged on the installation (sometime this happen). Since you used a rebuilt kit I would assume the bellow was good but you never know, is there a small crack on it?
Any ideas on why a unit won't pull a vacuum even after doing all this?
The only other vacuum issue I had with the vacuum unit (excluding the toilet) since this maintenance was done was with the vacuum switch. The symptom is the unit will run non stop or it will run and quickly loose its vacuum and restart again because the vacuum switch membrane is cracked and the air come through it. The easy way to find out is to remove the switch, clean the membrane on the switch and inspect it carefully.
@@svkiara1040 thank you, we've found that the inlet side was at fault, the generator itself was pulling a vacuum. Jubilee clips now tightened and all working :-)
great info.
Wow, just like my setup. Not! You must have a huge boat to have so much room to work in!
I get no sound
There is no sound. I choose to put only written details at important steps in the video
Now I’m sure that I will not buy it , to much maintenance, just go with the old Jabsco, 12 volt
my original bellow fit tight in the cylinder. the new one has a gap. normal? i would think it would need to be tight in the cylinder to create vacuum
As you can see at 6:15 in the video, my bellow is also not tight in the cylinder. This is not critical since the way this bellow works when it is pulled up is by changing the volume in the cylinder chamber by the volume it is compressed which create the suction in the inlet pipe as long as there is no leak from any other joint. What maintain the vacuum in this chamber (cylinder) are the 2 o'ring seals you see at 5:39 and 5:41 and also the duck bills from the outgoing pipe and the o'ring seal between the cylinder and the tank as shown at 2:40. As long as the bellow clamps (half rings black at 6:04) are tight to hold it in place this should be ok.