filling my water tank

Shaneyk88 · July 03, 2019, 09:29 PM

ok, next question. I want to make sure I do this right. I want to drain the water out of my water tank and refill with fresh water. The tank has been updated and the now has a sureflow pump. How do I drain the water and can I fill it with the hose hooked to the threaded inlet? Is there a specific order of operations? I took a picture of the outside water filling setup because it seems different then what is in the manual or what i see on the internet.

c farmer · July 03, 2019, 11:23 PM

My 82 has just a hole becide the threaded hole. The open hole fills the tank. The treaded hole is when your hooked to city water. Thats the way mine is anyway.

Shaneyk88 · July 04, 2019, 01:35 PM

Here are a couple more detailed pictures. my questions are:
If I hook up a hose to fill my water tank, do I need to open the valve that runs to the top of the tank?
Do I need to have the pump on/off
To empty the water that is in the tank now, do I have to run it out through the sinks and into the black tank and them dump or is there a valve somewhere on the tank itself I can open to drain it?
Thanks for any help you can give on these as I am a newbie.

joanfenn · July 04, 2019, 01:56 PM

Is that a gauge on the top? It looks like you can only fill your tank by a hose and yes you would have to have the little vent open to let the air out while doing it. But you would also have to have the vent open while you are using the water pump inside so it would not collapse. What am I missing here? There should be a hose with a valve on it coming out the bottom of the tank and going through the floor just to drain the tank but cant see one in your pictures. Maybe look on the exterior to see if there is a valve there somewhere in the vicinity of the tank.

Shaneyk88 · July 04, 2019, 02:48 PM

no gauges and cant find anywhere underneath to drain it? The tank has been updated but everything else seems pretty much the same. it now has a pump instead of the air pressure system and everything runs through the hot water tank underneath the sink.

joanfenn · July 04, 2019, 03:52 PM

No the gauge is on the fill inlet on the outside. It looks to me that you only can hook up to city water and the valve would show the pressure of the water so you won't blow your water lines apart with too much pressure. So does that mean that your system does both? You can use it with city hook up and hose and when you are boon docking you are using just the on board water. That is kind of cool, but you would have to open the vent either way. And yes when you are filling turn off the pump or the water will come out the overflow. This is my guess

Rickf1985 · July 04, 2019, 05:12 PM

I am not familiar with those older fill systems but it appears that the top of that filler where the gauge is will just unscrew by hand and you can gravity fill from there. The pressure fill looks like it would do the same thing but as was noted you would have to have a vent open somewhere to let the air out. As far as draining I would think there has to be a drain out the bottom, I have never seen a tank that did not have one. That suction line for the pump is a quarter of the way up the tank, does it drop down inside or do you run out of water at a quarter tank? I think you need to do some more line tracing.

Rickf1985 · July 04, 2019, 05:16 PM

I just noticed that little vent back behind the fill! That is the small copper tube leading up from the tank so that is your air vent and the tank could be filled either by pressure by attaching the hose to the fitting or I will bet that large top unscrews.

Shaneyk88 · July 04, 2019, 07:09 PM

Great, Thank You. the view of the line coming out of the tank is from the overhead, so its actually at the very bottom of the tank. the pump is mounted to the floor. No drain anywhere I can find. The tank is directly above the battery tray. I crawled all around under there and cant find any type of drain on the tank itself.
Thanks to all who have replied and helped me figure this out.

Rickf1985 · July 05, 2019, 10:55 AM

Now that you point out the orientation I can see it clearly. D:oH! D:oH! You would have thought that lovely original flooring would have been a giveaway.

So I guess the only way to drain the tank is pump it all the way out and make sure the RV is situated so that part of the tank is down. If it has sat for a long time you will definitely want to disinfect the tank with Clorox a couple times. Just Google disinfecting water tank or cleaning RV water tank and you will find a ton of info on how much Chlorox to use. It is not much.

YYC403 · June 02, 2021, 12:15 AM

I'll piggy back off this thread.

First time trying to fill the water tanks in my unit, has the same water inlet setup as the original poster and running into issues.

I open the air relief valve, hook up my hose to the inlet, turn on the water and all is good for a few minutes then water starts spurting out of the air relief so I shut the water down and close the air relief.

Within a few moments water is spurting out of the hose inlet hook up connection, due to too much pressure I'm guessing?

Also the little water line that's located on the driver side under the kitchen area is letting water out, and I believe this is the excess water line for when the tanks are supposed to be full... But there's no way the tanks are full.

It feels like only water is going into the lines and not the tanks? Although I would guess that the water lines going to the kitchen/bathroom wood come directly from the tanks?

So I'm not sure what I'm doing wrong, this is the original air compressor setup that would have come with the unit, does anyone on here have experience with this setup and any guesses as to what I'm doing wrong?

Any help would be appreciated

TerryH · June 02, 2021, 01:25 AM

I do not have the same set up as you, but consider this:
Your city water connection and the hose you are likely using have an ID of 1/2 or 5/8 inch. Your vent hose may be 1/4 inch ID.
Once you attach the house hose to fill your tank you are creating a 'closed system'.
Meaning that, unlike your fuel fill hose, there is no opportunity for excess air to relieve, other than the considerably smaller vent tube.
Your tank holds two things - water and air. Increasing the volume of one means you must exponentially decrease the other. This will only happen satisfactorily if the ingress and egress volumes are equal, or better yet, higher on the egress side.
What many have found to work best is to use a funnel in the city water inlet and let a hose fill it at low volume.

YYC403 · June 13, 2021, 05:09 PM

Still trying to sort out the water system but leaning towards something is hooped.

One thing I did notice is that in the home owners manual that came with the unit it says to not run the air compressor while adding water, however in the owners manual for the 75 Brave & Indian that's offered under the owners manuals on this site, it says to run the air compressor while adding water.

Does anyone know which is the proper method?

Oz · June 14, 2021, 09:11 PM

If your unit has an overflow valve on the filler, you don't need to run the compressor because the overflow tells you the tank is full as much as needed before filling it up all the way, which you don't want because then there's no space left for the air to build pressure.

If you don't have an overflow valve, then you definitely need to run the compressor because you won't know the tank is too full of water until it's too late, and then you have to drain some.

The owners manuals on this site are the same ones Winnebago originally issued with the RVs. Why there is a discrepancy with yours could be that it was printed, and then Winnebago discovered an error and corrected it later. I don't know, I don't have all the manuals memorized, lol!

Unless... it's been changed in the decades since it was built. And you don't know that, so..

Seriously, the best thing to do is convert to an on-deman pump. You just fill the tank all the way with water and that's it. The pump comes on when you use a water outlet. And, the pressure is consistent, not like the compressed air system, which gradually reduces water pressure until it's low enough for the air pump to kick in. It's annoying, to say the least.