Jon’s Bus Conversion Part 43 – Mod – extend your water tank by using the on-board pump

Jon’s Bus Conversion Part 43 – Mod – extend your water tank by using the on-board pump


My water tank is not big enough and I do need to install
a bigger water tank but I can find one that fits that’s really expensive – or a cheap
one on ebay that I suppose is surplus, but it doesn’t fit.
So as an interim solution, I saw this video – and I’ll post a link to it – where they
show you how to add a bypass to your existing system so you can use your pump to fill up
your tank from an external – like a blue jug. This bypass valve here allows me to fill my
tank up from city water. Between these two, I can use this – these
two together and I’ll be able to fill the tank up from – like a blue jug or collapsible
jugs or something like that to make it easier for me – and extend my water.
Even if I had a bigger tank, it would be nice to have this.
But before I hook that up, I thought it would be useful to take a quick look at a typical
RV plumbing thing and I’ll explain what I’m about to do with that 3 way bypass valve.
Here’s is the typical RV basic setup. We’ve got a water tank down here, we have a self
priming pump here and one or more faucets in the RV over here. When you turn the faucet
on, the pressure drops in the line and causes the pump to go on. And pump more water. Now
in the real world of course we need a way to fill the tank so the RV will have what’s
called a gravity flow inlet, where you can stick a hose or something like that in there
and fill the tank up. But most RVs at least most if not all – have
what’s also called a city water hookup. This is a pressurized hookup where you can hook
the hose up directly or something like that. And supply the RV with water directly from
the city water hookup. Your house or an RV park or something like
that. Now what you should be aware of if you’re
doing this yourself – like I did – you want to be aware that there are two important factors
to this. You need these two one-way valves where I’ve shown them here.
Most of the time the RV pump will probably have it’s own one way valve. But you definitely
do need one here. And if we do a little thought experiment, we can see why.
Suppose the city water is not hooked up what would happen in the water from the pump could
come out here and could flow out through the city water connection instead of going in
the RV. Similarly, when the city water is hooked up, this configuration is an auto switch.
So you don’t need any kind of valve or anything here. What will happen is when the city water
is hooked up, you turn this faucet on – the pressure drop is not seen by the pump because
the pump is on the other side of the one way valve. The city water is going to keep the
pressure and supply the RV with the city water. Now having said that, a good modification
to make that a lot of RVs have this as well. But if yours doesn’t, or you are building
one, you can add this. You can put a bypass valve in here, that circumvents the one way
valve and so what will happen now is that when you are hooked up to city water, and
you flip this valve on, the city water will flow – instead of going into the RV, it will
flow down here through this valve and into the tank.
Although of course you can always use the gravity flow – but this is kind of a pain
getting a hose out, sticking it in – a lot of times it will leak a bit of water because
it’s not an efficient way of doing things. This is much preferable. Instead of doing
all that, you just flip the thing when the city water is on and fill your tank.
Now the modification that I’m doing today with that three way valve that I just showed
you is – I’m putting this between the pump and the tank like this. Normally if you are
running off the pump, the bypass valve will be shut and this will be pointing toward the
tank and so when the pump pumps it will pump water out of the tank. But if you want to
fill up your tank from external blue jugs or those clear plastic jugs or something like
that, whatever – you can flip this in this direction and flip this bypass on and then
what will happen is the pump is going to pump the water directly out of the blue jug or
clear plastic jug or whatever and it’s going to go down here through this valve here and
fill the tank up. So this is a really cool way of using the
on-board pump to pump water out of an external source and put it directly into the tank.
So that’s what I’m going to be doing now. For my bypass to fill the tank from an external
source – this is just a regular RV water inlet. And it had a kind of spout thing here for
entering the water – this one only has a gravity hookup not a city. Which is fine for what
I need. Anyway it had this spout. I cut it out with
a hole saw. Now I cut a piece of metal. I’m going to stick it in like that and see if
I can get the valve – mount the valve in there. The valve is going to go in kind of like this.
But it will be surface mounted. And then I’ll have a hose connection here so I can screw
in a hose, flip the valve and fill the tank up from an external water tank.
Come on guys admit it. You’re dying to take a grinder to the side of your car but your
wife won’t let you. Well – I’m not married – ha.
It fits! It’s on.
So what are you doing? I’m going to hook up the pump to the middle.
The middle one of those. So I just thought I’d show you. If you’re
not familiar with this. Here’s the gravity flow input I was talking about.
You see that’s just kind of a spout here. You can stick a hose or something in there.
Here’s the city water hookup. And you do screw a hose in there with threads.
Here’s how this turned out. Here’s my bypass. So this is set to pull water out of the tank
right now. Let’s see what happens when I flip a few switches..
I went ahead and screwed a hose in there. Just for laughs – lets’ take a look at what’s
behind there. There’s where my pump is right there. Normally
it would have gone over to this right here directly what I’ve done is to put this valve
in the middle right there. And then this flex hose right here is the other side of the valve
and I just ran it to a hose bib right there. Where this hose is here.
I have a 30 gallon tank. So I could buy 6 of these and obviously they store easily.
This one’s full – and double my capacity. I’ve already got a couple of blue jugs and
two of these. So the blue jugs are 7 and two of these – so that’s already 27 gallons. So
I’ve almost got double capacity with these external tanks as it is. So let’s see how
I’d do it. Turn the pump off. I’m going to flip my bypass valve so that water goes into
the tank instead of the RV system. I’m going to flip the 2 way valve so it’s
drawing from the external instead of the tank. Now when I turn the pump on, it’s going to
start drawing water out of there. You can see it’s already drawn about 1/2 of it down
there. And there goes the last of it. So trust me – if you’ve been doing it the way I used
to do it and then you add this modification, you’ll be liking life a lot more – this is
sure a lot easier than how I used to do this.