Fresh Water Gravity Fill Problems

[RV-Writer]

Hi all,

My gravity fill is a disaster. Any time I put water in (either through the gravity fill tube or city water/tank fill valve) and get like 2/3rds full, It drips out the fill valve for hours even when level.

Not a slow drip but pretty fast. And if I take the lid off, it POURS out in a rush.

Also, today I put my jacks down to raise passenger side wheels off the ground to put on my tire covers, and water flowed out big time.

Any thoughts? This has been going on since I bought it in 2016.

My tank monitor is usually pretty accurate though.
Thanks

[Alan_Hepburn]

Sounds like your vent line is obstructed in some way - maybe kinked from a poor installation.

[RV-Writer]

Originally Posted by Alan_Hepburn

Sounds like your vent line is obstructed in some way - maybe kinked from a poor installation.

The parts I can see seem ok. Thought about getting a loooong wire and try to push it through the hose to see if I get any resistance. Maybe I should use air compressor and try to blow it out?

[AveryF]

I don’t have an answer but I’d be hesitant to try compressed air through the vent line because of the possibility of forcing a foreign object into the fresh water tank. I would be afraid that might cause other problems later on.

[Skip426]

Fresh tanks are usually clear plastic , I'd say you need to get eyes on the tank to check your monitor sensor accuracy .

JMHO : If you use the city fill valve and water comes out the gravity fill cap the tank is full .
Water dripping out the city fill , after use , would indicate the back flow isn't working , time to replace.
What happens when the 12 volt pump is in use?

[RV-Writer]

Originally Posted by Skip426

Fresh tanks are usually clear plastic , I'd say you need to get eyes on the tank to check your monitor sensor accuracy .

JMHO : If you use the city fill valve and water comes out the gravity fill cap the tank is full .
Water dripping out the city fill , after use , would indicate the back flow isn't working , time to replace.
What happens when the 12 volt pump is in use?

My fresh tank is not visible at all. But I have had my 90 gal tank empty and watch my guages move from E through 1/3 to 2/3 to full in expected times during fillng. When I get water out of my gravity fill while using the city water connection, my tank is close to full on the monitors. I find if i dont open my fresh water valve full blast while filling it is better but it drips out of the gravity fill for hours after filling at any case. If I removed the cap, it would pour out big time, so the cap helps.

Water doesnt come out of the city fill but out of the gravity fill hole when using either the city/tank fill water hook up or the gravity fill method.

Its almost like my gravity fill hose is lower than the tank or something

I dont understand your pump question can you clarify?

Thanks for your help

its weird

[Old-Biscuit]

Gravity fill line could be sagging which when tank is full can cause a syphoning effect
Tank vent line could be sagging...filled with water so tank doesn't vent properly

Tank overflow...that should be pouring water if tank is overfilled
No water from overflow then vent and or gravity fill line is the issue

You will have to ACCESS the tank/lines to verify/correct OR live with it like you have since 2016

[RV-Writer]

Originally Posted by Old-Biscuit

Gravity fill line could be sagging which when tank is full can cause a syphoning effect
Tank vent line could be sagging...filled with water so tank doesn't vent properly

Tank overflow...that should be pouring water if tank is overfilled
No water from overflow then vent and or gravity fill line is the issue

You will have to ACCESS the tank/lines to verify/correct OR live with it like you have since 2016

Thank you. Any idea where the Tank Overflow is? I dont see one aywhere. I will have to tear out some thigs to try and geat a visual on my tank and hoses

[Old-Biscuit]

After looking up and reading the Owners Manual (1997---no 1998 available) it makes a statement about opening the gravity fill door when filling via city water to allow excess waer to escape when tank is FULL

Section 4-1 Pg 105
https://big.nyc3.cdn.digitaloceanspa...715&focal=none


Guess that means No OVERFLOW Pipe.....just comes out the gravity fil port

[RV-Writer]

Originally Posted by Old-Biscuit

After looking up and reading the Owners Manual (1997---no 1998 available) it makes a statement about opening the gravity fill door when filling via city water to allow excess waer to escape when tank is FULL

Section 4-1 Pg 105
https://big.nyc3.cdn.digitaloceanspa...715&focal=none


Guess that means No OVERFLOW Pipe.....just comes out the gravity fil port

Thank you OB

I will keep tinkering with it. Not critical but a pain.

I recently had a faulty city water valve that was filling the fresh tank when on city water. Replaced it hoping ALL my problems would go away No such luck

[Gary RVRoamer]

I think Old Biscuit has identified the likely problem. It fits your symptoms perfectly and could easily result from an assembly error at the factory, perhaps a worker who was in a hurry or not trained for that specific task. An all-too-common occurrence at RV factories.


I had a similar experience with the fuel tank on a 2002 Dolphin coach and struggled with it for a couple years before crawling underneath and fixing the sagging fuel & vent lines. I shortened the line by about 6" once I eliminated the droop in the hoses.

[ROUGHRIDER3]

Check the check valves for proper operation.

[Old-Biscuit]

Originally Posted by ROUGHRIDER3

Check the check valves for proper operation.

Which check valves should be checked