# hymer water tank overflow



## turls (Mar 18, 2007)

Hello to anybody who might read this because i doubt very much i have posted it correctly. 
My problem is when filling my water tank the lid on top the tank with the pump pipe and lead coming out of it will leak as the tank is getting overfilled instead of it just running out of the filler inlet and onto the floor.Not a big problem you might say ,but by the time you've realized you've overfilled (because it takes so long you always find something else to fiddle with) its already running out under the units over the carpets and by the time you get back outside to pull the pipe out there's still a nice little river still flowing inside.
Ok so i will bung up the pipe and the lead with a sealer, but there is still a breather on top of the tank that has a one way valve which i need to extend a bit higher so its higher than the filler ,BUT also on top of my tank i have 3 other pipes which im guessing 2 are vents and the 3rd pipe runs under the tank to where im not sure but thought it might go out underneath the van as an over flow , can anybody confirm this ???? 

any help with any of this (proper way to seal the cable and the fitting which is loose going through the lid for the waterpipe much appreciated ) CT 1 is what i have in mind!!!

Many thanks nick


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## bognormike (May 10, 2005)

what year & model is it?


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## 113016 (Jun 5, 2008)

I think you will find one pipe will be the water supply, one to the toilet and one to the breather.
On my previous Hymer Tramp, where the wire came through, it always leaked a little, but never came over the top of the cap.
It was one of those jobs I never got around to sorting out!


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## turls (Mar 18, 2007)

*hymer overflowed watertank*

Hello the van is a 96 hymer 564 rhd.


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## Chausson (Oct 17, 2006)

Hi I shall be watching this topic as I have the same issue but never gave the overflow a thought, to be honest I did not realise there was an overflow.
I thought there must be a crack in the screw on part or the seal was not making a good seal, I shall have to have a good look at it.


Ron


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## buzzers (Aug 25, 2012)

*Overflow in Hymer*

Hi,
I have a 1994 B644 and there is an overflow pipe that is positioned half way down the length of the tank and about 3/4 up the tank. When filling I know when it's full as I will hear water pouring out of the overflow on to the ground. The tank cannot be filled to the brim because of this overflow outlet.
I would suggest that you check that the previous owner hasn't capped off the overflow outlet. he may have done this in order to get an extra 20 litres or so into the tank, as the overflow results in 3/4 full as the maximum you can get.

Gary


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## premiermotorhomes (Feb 13, 2008)

Buzzers,

Chausson also use an outlet like this on their current model ranges, this is done to allow the vehicle to meet certain payloads, as they will use one tank on many models.

If anyone does decide to modify the overflow then just make sure you take care you don't exceed your Gross weight.

Regards,
Chris


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## 113016 (Jun 5, 2008)

premiermotorhomes said:


> Buzzers,
> 
> Chausson also use an outlet like this on their current model ranges, this is done to allow the vehicle to meet certain payloads, as they will use one tank on many models.
> 
> ...


Good morning Chris.
So do I take it that say for instance Chausson have a 100litre water tank that a person could not get 100 litres to stay in without modifying the overflow?
As a wilder this is interesting as water quantity is life support.
I would probably fit some sort of tap, or move it higher, as I would like the control myself and not be limited.


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## premiermotorhomes (Feb 13, 2008)

Good morning Gratth, 

Yes, Chausson for example use the same 100ltr water tank in all their models, but the overflow could be fitted at a different height in different models to provide Chausson control of vehicle payloads i.e. if the vehicle is a panel van it might have the the overflow higher up to hold a greater water volume as its weight is low and would have a high enough payload to compensate. However a large coachbuilt may have it 75% up the tank as there is a lower payload available due to the greater weight of the vehicle.

Whether the brackets used to secure the tank are able to accomodate the additional load I could not comment, but anyone who chooses to make an adaptation such as this needs to remember not to exceed thier Gross weight in doing so.

Regards,
Chris


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## 113016 (Jun 5, 2008)

So Chris, what do Chausson advertise their water tank capacity as.
Do they state a different capacity on different M/H,s?


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## premiermotorhomes (Feb 13, 2008)

Hello Grath, 

I don't get involved in Sales, but as I understand it they will advertise different capacities for different models. I can't say of course its the same tank in all cases, but as far as I know certainly in some of them.
Regards,
Chris


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## 113016 (Jun 5, 2008)

Thanks Chris, I just wondered  
I suppose it's all to do with vans generally getting longer and owners wanting ever more gadgets. They have to do something to get the weight down.
I only noticed a few months ago that Hymer are now stating a 20 litre water capacity for when travelling and also only one gas bottle, where before it was always 90% water , fuel and gas!
These are pretty important things to a wilder and some dealers don't point this out. Inexperienced M/Hers could fall into a trap and be foul of the law  
Each manufacture will do it their own way and it would be better if they all kept to one standard.


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## premiermotorhomes (Feb 13, 2008)

I think you're right with your assumptions, as things have moved along and we want to get more out of our vans then they must get heavier to acomodate and the onboard tank capacity's would be the obvious weight saving feature to adjust in the figures.

Yes, I agree tank capacity may not be advised by the dealer all the time, but whose responsibilty is it to ensure awareness, the customers, the dealers or shared?

I don't think we will ever see a day where this would be standarised due to the sheer variation in construction techniques and standard equipment will alter the weights on every motorhome. Of course as soon as a customer starts to add extras and loads up then you can't just work on the figures provided in the tech specs, you've then got to find a compromise.

Regards,
Chris


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## Bob45 (Jan 22, 2007)

My 2005 Hymer 655SL has 75% full overflow which can be turned both off and on. I seem to remember the manual mentions safer driving conditions or more stable with less water on board.
I tend to drive with a quarter tank of water and only turn off the overow when we are staying put in one place for a few days.
Bob


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## 113016 (Jun 5, 2008)

Just as well that our van has the carrying capacity for a full water tank and even more. We also carry extra water :lol: and still below the 3500kg  even with the geny, tools and everything else.


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## Chausson (Oct 17, 2006)

Bob45 said:


> My 2005 Hymer 655SL has 75% full overflow which can be turned both off and on. I seem to remember the manual mentions safer driving conditions or more stable with less water on board.
> I tend to drive with a quarter tank of water and only turn off the overow when we are staying put in one place for a few days.
> Bob


Bob
Can you tell us how you able to turn the overflow off and on please.

Ron


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## turls (Mar 18, 2007)

Ron im glad you asked how he turns off and on the overflow (that was going to be my first question) 
I see they are lots of interest in this stuff i never even considered.
My tank has 2 fittings on top of the tank joined togeter with a t piece and its the other pipe coming out of this t that goes under the tank which is the one in question as to wether its the outlet should the 2 on top of the ever get water go up them from an overfilling tank . (think i might pop out and pull the pipe off and blow down it and get the misses to listen for air under the van !!!! pigs might fly too tonight its freezing out ,,, 
Any thoughts on sealing the through fitting for the water pipe and the power lead to the pump ???? 

many thanks nick


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## turls (Mar 18, 2007)

Hi i have been out and pulled the pipe off and had the misses blow down it and it does come out underneath the van,so a bit closer to solving the issue ,,,,


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## Chausson (Oct 17, 2006)

turls said:


> Hi i have been out and pulled the pipe off and had the misses blow down it and it does come out underneath the van,so a bit closer to solving the issue ,,,,


Hi Nick
Many thanks for the info, I shall go look inthe morning to see if mine is of the same setup as yours.
I did look through the manual this evening, all I could see was that the display unit when its reads 75% this means the tank is full, hymer says it is a saftey issue not to fill the tank to 100% if you have a tank holding 120 ltrs, I dont see how you can switch it off and on, the overflow I mean, on that we shall just have to wait to see what the other person has to say.

Ron


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## Bob45 (Jan 22, 2007)

Chausson
We lift up cushion and seat on top of the water tank. On the end of the water tank nearet the van side there is a tap on the over flow pipe for turning it on and off.
Simples.
Bob


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## Chausson (Oct 17, 2006)

Hi Bob
Thanks for that I shall have to have a look on mine but have honestly never seen a tap of any sort that's not to say there is not one there.
Again thanks.

Ron


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## turls (Mar 18, 2007)

Hi 
I have fixed all leaks on the overflow ,can now leave the hose pipe running and the water just spills back up and out of the filler , i have added an image just showing my tank setup ,
As you can see i have 2 pipe fittings at the top of the tank ,which are joined by a t and that then goes under the tank and out the bottom of the van ,but what i find a bit strange is the other t which incorporates a non return valve which would allow the water up the flow pipe to the tap ????? why ?? hope this also helps someone else .
Nick


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## Chausson (Oct 17, 2006)

Hi Nick
Thanks for the photo, mine is simular but I dont have all that pipe work that you have, I shall have to have a further look into it.
Again thanks.

Ron


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## peejay (May 10, 2005)

Hi Ron,

I don't know if yours is similar but our (Fiat) overflow tap is in the L/hand side locker....



















I think the Merc chassis has slideout trays as opposed to lockers, perhaps its behind the tray?

Pete


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## Chausson (Oct 17, 2006)

Hi Pete
Thanks for your info, I have found that valve which is tucked down the tight side of the water tank and the wall, I now have to make a tool to allow me to open/shut the valve. This valve is the one Hymer fit to only allow the tank to be filled to 70 litres instead of 120 ltrs as a safety feature.


Ron


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