Additional Van water tank

Yep, you're on the right track, I'd say. You're trying to make water run uphill. The hose joining the 2 tanks together needs to be as flat/level as possible, with no raised bit. You should be able to run it "along" the chassis, instead of "over" the chassis....

Hope this makes sense.

Cheers

Roachie

Yep, you are right, you are expecting the hose to syphon, but it won't do it unless the hose is full of water. May work if first tank is full, and hose doesn't rise above the top of the full tank. Better still if you can get the hose as low as you can near the bottom of the tank.

Install one larger single tank?

A seperate filler for each tank and a three way direction type tap supply hose from the two tanks is another option. That way when one runs out you switch the tap to supply from the second tank Giving you a good idea of water consumption and handy if you need to fill water but don't want it with your drinkable stuff in which case you just use the spare outlet port on the tank.

Do both tanks have a working breather??

Anyway, if it were me, I'd have the two tanks plumbed separately - so one can be kept aside of drinking water, and the other can be topped up as necessary with "dodgy" water.

I have fitted many 2nd tanks to vans and the only way to fil them to 100% capacity is to pressure fill them.

Most tanks are fitted with 2 lower (Drain) fittings. Drill them out as most are not drilled at the factory. Use one as your suction side for the pump and the other as a drain / filler via a ball valve tap. Fit a 25mm ball valve between the tanks on the filler as an isolator so you can drain the tanks one at a time. Also fit a tap to each suction fitting so so can isolate you usage. I use my front tank first and also fill this tank with any 'Suspect' water so it is easily flushed.

Close all taps and pressure fill the tanks from the drain fitting one at a time. You will get them 100% full this way.

Regards Derek.

GeeTee,
I have fitted 2 tanks to my van and used a Gas type 3 way fitting for both filling and usage. Both tanks fill from a domestic hose with no trouble at all. Only inconvenience is that you have to change the taps but you have control of what water is used to fill them & a better idea of usage.

I too have fitted a second tank to our Freedom Poptop. It is positioned behind the axle. Fortunately the filler is at the top with the outlet at the bottom. However I have always had a second filler hose. I thought of the single filler idea but it was actually harder to control the flow to each tank. I recently fitted a Camec lockable filler cap to the side of the van with the hose, etc entering under the single bed and out the floor. There are pictures on the JUGA (Jayco User Group Australia) via Yahoo of the cap setup.

The plumbing only involves outlets to the sink which are via a pair of Shurflo pumps in series. The rear pump can be isolated when only pumping from the front tank. The hand pump in the van has been replaced by a normal sink type tap from Bunnings.

If you need more info give me your email address and I can send pictures.

Wizard
Gold Coast