Losing 25% from a full Fresh Water Tank

I have just taken delivery of a 2010 Suffolk and have only managed a single night stop. Before departure I filled up the water tank which overflowed (as per the Owners Manual 7-1) and checked the gauge which registered 100%. On arrival at the site ( 120 miles mostly on Motorway) I noticed the water level now showed 75%. This seems a large loss , over 17 litres, through the breather pipe. Is this normal?

Can the breather be extended in any way to reduce the loss?

I think that the water guages are notoriously unreliable. Did you confirm the water loss by re-filling the tank on arrival to get an exact figure? The guage on my van only registers quarters ie empty, ¼, ½, ¾ and full.

squip

Thanks Squip, yes it took quite a bit of water to fill again but I did not measure it. I did a second trial for the homeward journey and exactly the same happened again.

This is a link to a thread on MHFacts on this subject http://www.motorhomefacts.com/ftopict-68859-water.html+tank+loss

Thanks for the reference I will drop the tank and have a look.

It would seem stupid to only fill to 75% as a solution.

As posted on MHF - are you needing to travel with a full tank of water - equivalent to carrying another body on board?

If you travel across Europe in the winter there are many occassions when you don't know if fresh water will be available. But surely the point reallly is that tanks should be designed to

retain their contents and it seems they don't. Perhaps Autosleepers should investigate and find a solution, there certainly seems to be a problem.

Fair 'nuf...........ah, the days when we crossed Europe with a 10 litre fresh ans waste tank under the sink in a Hiace - things seemed simpler in these days......

When I fill the tank on our Trident I notice when it becomes full it overflows from beneath the van.

I mentioned this on here a while back and someone told me (think it may even have been Squip?) that the tank has ventilation holes? So if this is the case and yours is the same, when you are driving with a fullish tank then I'm guessing as the water sloshes around as you drive and brake you can't be off losing some of the water on board?

All the above posts are perfectly understandable and there is no mystery involved but to lose 17 litres is too much , I was hoping
the problem had been solved by some handyman who might enlarge on how to reduce the loss.

I agree it's unacceptable for this kind of loss - and you shouldn't have to do it to a new van but I'd fit an extended "elbow" on top of the tank and take a breather hose to a higher place on the van (if there's space - the clubman has) . Then fill in/cover the existing breather holes.

http://www.caktanks.com/files/cak_catalogue_2011/2011%20CAK%20CATALOGUE%20LOW%20RES.pdf

Thanks Dandy I'm off to drop the tank to have a look. CAK tanks have a great selection and I have dealt with them before, one of the pipes must be capable of doing the job.
I will report back regarding progress.

If it was me - I'd also be reporting back to AS and tell them the current arrangement is unacceptable.

I've spoken to Mark in Service at the factory a few times and he appears to listen.

Yes been there done that .........the reply was "you can expect this to happen!!!!!"

Anyway I have just been under the tank and the breather is a small outlet on the the front SIDE of the tank obviously near the top. Lo and behold attached to this
is about 20" of blue water pipe which is not supported and hangs down BELOW the bottom level of the tank. So for starters I have re routed the pipe which now vents upwards just above the top level of the tank. I will give it a test run tomorrow and fingers crossed, problem solved or at least reduced.

And the other thing is.......When I first got a 'van with a hot-water system it took a while for me (not being that bright you understand) to realise that, yes the fresh water tank might be nice and full, but switch on the pump and it transfers 10L into the heater tank. Then all of a sudden the gauge is showing only 3/4. Doh, where did that go?

nforrgolf wrote:Yes been there done that .........the reply was "you can expect this to happen!!!!!"

Anyway I have just been under the tank and the breather is a small outlet on the the front SIDE of the tank obviously near the top. Lo and behold attached to this
is about 20" of blue water pipe which is not supported and hangs down BELOW the bottom level of the tank. So for starters I have re routed the pipe which now vents upwards just above the top level of the tank. I will give it a test run tomorrow and fingers crossed, problem solved or at least reduced.

That'll be yer answer - the water is syphoning out of the tank!

well done - now go and rattle AS's knuckles

Wo - dont go stripping the tank out yet.

Your Suffolk is basically the same van as ours but on a Merc. The water indicator is a rough guide only. Fill up to 100%, turn the tap on for 30 secs and its down to 75% for a cupfull of water! I know its very annoying but you havnt lost water its just the way the Sergent panel and indicator is.

Our van has been like that since new along with other models using the same system.

roli wrote:Wo - dont go stripping the tank out yet.

Your Suffolk is basically the same van as ours but on a Merc. The water indicator is a rough guide only. Fill up to 100%, turn the tap on for 30 secs and its down to 75% for a cupfull of water! I know its very annoying but you havnt lost water its just the way the Sergent panel and indicator is.

Our van has been like that since new along with other models using the same system.

Agreed, but if the breather pipe is dangling down below the water level it will syphon out til it gets to the pipe level. "U" tube principal

Tube re-routed: after a short run I am pleased to report the gauge remained at 100%.

Simples!

Thanks to all for the inputs, I am very impressed with the forum.

nforrgolf wrote:Tube re-routed: after a short run I am pleased to report the gauge remained at 100%.

Simples!

Thanks to all for the inputs, I am very impressed with the forum.

Excellent tip / advice there for other members nforrgolf

I'm up to Coniston this weekend with a full tank, so will be watching for this and requesting a modificaton if I leave the water all over the M6... thanks for the advice

DuxDeluxe wrote:I'm up to Coniston this weekend with a full tank, so will be watching for this and requesting a modificaton if I leave the water all over the M6... thanks for the advice

Without seeming nosey, why are you travelling 300 miles with that weight of water on board when you can fill up at a service station etc. in the Lake District??????????

Good question....

1) because I can! - also to see what happens as above
2) Can't be bothered to fill up en route - it is a fiddly filling thingy
3) The campsite has not much in the way of facilities and it might be a trek to the tap
4) We tend to fill up before travelling anyway, though I accept that this is not the most cost effective means of doing it. Then again, if I were to worry about cost effectiveness and saving a couple of quid, I would not have spent £50K on a van in the first place.....

Hope that clarifies things a little (not) Cheers

DuxDeluxe wrote:if I were to worry about cost effectiveness and saving a couple of quid, I would not have spent £50K on a van in the first place.....

Like your style DuxDeluxe

We rarely ever fill our tank, usually just empty one or two of our 5ltr water carriers into the tank before we set off so we can at least pull over on route and have access to water should we need it, then just top the tank up daily as we need to but tend to empty the tank for the return journey. It's down to individual choice at the end of the day!

It is habit, I suppose - not worried about the payload as it is huge on a 4 tonne broadway and some places it can be a pain to fill up (Poole yacht club, where it is easy if you have a boat but not if you are in a van on the marina wall - Osprey dinghy championships, before anyone asks.....)

Cheers everyone. Just arrived at Seoul airport to fly back to find my flight is delayed by 4 hours and I miss my connection. Not a happy bunny but at least the Cathay lounge is nice and they have sorted alternative flights