Fresh Water Filling

We took our Legend away for the first time over Mothers Day. I filled with fresh water before leaving home.

1) I expected to know the tank was full when the filler neck filled up, but I heard water cascading and looked underneath to see it flowing over the edges of the tank. It didn't seem a satisfactory system but I assumed it was from a vent/overflow. Is it normal?

2) I'd set the gauge at full and was surprised when we arrived to read it at around half full. (journey 90 miles). I needed to add over 20 litres to bring it to full. Is this normal?

3) I filled up this weekend to see what happens. Again water cascaded out after which there was a heavy drip from both ends of the tank. The dripping had stopped by the following morning and the gauge was reading about 3/8 full. I've crawled underneath to check where this water may be pouring out and discovered access to the top of the tank is impossible. The best I could do is poke my camera up through about a 1" gap between the chassis member and side of the tank. I've discovered there's a small cover around which is what appears to be a white seal. This has a break in it through which water must be passing, and there are indications of water pooling on the top. I had to put in about 20 litres to start overflowing again. I'm baffled as to how the water is leaking to such a low level. I can see no sign of a split in the tank walls.

After I'd filled, I switched on the pump to fill the hot tank and pipework and then topped up the cold to overflowing again and switched off the pump. It was still holding pressure next morning so water was not feeding back into the tank.
The gauge may of course be faulty, but it doesn't explain having to  add 20 litres.

Can anyone explain this please?

Tony

1. I think that it is normal for the tanks installed in 1996.
2. No. If it overflowed when filling, the tank was full. Assuming no consumption, it should have remained full. Certainly not 20 litres short of full..
3. Must be a leak, from split in tank or possibly from the gauge probe (if there is one).

Cymro

My tank (Clubman, 1997) does exactly the same. You know it's full cos it pours over the sides, thankfully under the body, not in the hab. I only use it for washing with, not drinking, my thought being if it can pour out, it can also let crap in.

The guage...wildly inaccurate. Reads full one minute, then 3/4 next time you try it, without moving, and with nothing leaking.

Don't forget, you lose quite a bit in the piping and the water heater when you fill from drain down. A few gallons.  Also lose a bit when driving, as it sloshes about. I try to travel with not much more than half a tank, because of that, but also because of the weight. A pint of water is a pound and a quarter! (Weight? Where's IanH when you want him! )

Peatlander 2 wrote:My tank (Clubman, 1997) does exactly the same. You know it's full cos it pours over the sides, thankfully under the body, not in the hab. I only use it for washing with, not drinking, my thought being if it can pour out, it can also let crap in.

The guage...wildly inaccurate. Reads full one minute, then 3/4 next time you try it, without moving, and with nothing leaking.

Don't forget, you lose quite a bit in the piping and the water heater when you fill from drain down. A few gallons.  Also lose a bit when driving, as it sloshes about. I try to travel with not much more than half a tank, because of that, but also because of the weight. A pint of water is a pound and a quarter! (Weight? Where's IanH when you want him! )

1 litre weighs 1 kg.
Carver water heaters (which is what you've probably got) holds 13 litres.

I may have got this wrong but my understanding was that the conductivity probes in the tank are in steps, not progressive or linear. They basically indicate when the tank has reached 25% full, or 50% full, or 75% full etc.

So if the gauge reads 50% full then the tank could actually be 74% full, and so on.

Having said that, my impression as a recent new owner is that the gauges are erratic and pretty useless. I just fill up every day and carry a spare 10 litres of water.

Mine too!

My adage works perfectly here!

A tank is full when it overflows
It is empty when nothing comes out of the open drain tap.

Gauges do one thing well, they lie!

1litre water weighs 1Kg
1litre diesel weighs .75Kg
1 litre propane weighs circa .55Kg

Pints are for beer and people who think in pounds, shillings and pence!!!!

Paulmold wrote:1 litre weighs 1 kg.
Carver water heaters (which is what you've probably got) holds 13 litres.

I have a propex water heater. Holds 13 litres though. Or for old fashioned folk like me, 2.86 gallons.

Furrin measurey-ments, fah. I'm a luddite and proud!

Cymro wrote:1. I think that it is normal for the tanks installed in 1996.
2. No. If it overflowed when filling, the tank was full. Assuming no consumption, it should have remained full. Certainly not 20 litres short of full..
3. Must be a leak, from split in tank or possibly from the gauge probe (if there is one).

Cymro

I must change my details. My vehicle is now a '98.
I'm wondering now if I do actually fill. I stop filling because there's the overflowing water but it may take some more if a 'wave' is causing it.
Yes there's a probe I'll take a look if possible - Would it be fitted into the top of the tank though.

Probe is in the top of the tank on mine... Accessible by taking the seat base out. Big hole around the pipe, no wonder there was a draught and a load of road dust. (Vinyl collar seal? Why would you fit one of those?) That being said, I reckon it would be very difficult to access.

Thankyou for your responses. If I put together the comments on gauge accuracy and the possibility that I may not actually be filling to capacity, the problem may not be so severe.