water tank 2008 nuevo

the water tank of my Nuevo leaks not catastrophically just a couple of liters per day it doesnt matter if the tank is full or near empty the leak is the same  so its not coming from the overflow.

It doesnt seem to be coming from the large inspection hatch, rather is seems to be coming from a ring which runs around the hatch about 50mm away - but its really hard to tell exactly where it is coming from.

are these tanks prone to fail or is it just the hatch cap that needs tightened and or a new gasket?
If the tank has failed can it we plastic welded?
or if a replacement is needed does any one know if a larger tank can be fitted?

the leak is an irritation more than any thing but with such a small tank (65L I think)  every drop is precious when wild camping

If it is the seal of the inspection hatch, assuming you can unscrew it a goodly dressing of vaseline or non setting sealant will do the job. It's just a massive "O" ring, but the hatch is likely to be very tight and difficult to unscrew.

It sounds more like the hatch housing from what you say. To be sure of fixing this you will probably need to drop the tank, take off the flange, clean and replace with Sikaflex sealant. Messrs A/S may have used stainless steel nuts and bolts to secure the flange, but they didn't on the waste tank of our previous van, so they could be rusty inside the tank.!!!! (You may be able to access the nuts by reaching in through the hatch, but I can't remember clearly enough how the plate was fixed.)

It's not an easy job, so I would first try scrubbing the outside where it leaks as clean as possible. Then roughen the surface a bit with coarse sandpaper before "fingering" in a bead of Sikaflex all the way round the joins - in fact everywhere it might be leaking.

Sikaflex sticks like you-know-what to a new blanket, and may well do the job very easily and for a cost of less than a tenner.


P.S. Just saw Peter's post. Our hatch looked like No.3 on the diagram, but I can't see the mounting flange/plate either.

page 20 at the link  refers to waste tanks my leaking tank is the fresh water one similar to those on page 14 of the link, it has a large 250mm (ish) red screw on hatch cover facing down towards the road there is a ring on which this cap is mounted which appers to be held to the tank with several self tappers (may be bolts)

spraying it with seems like a good idea!

right you are!
I was using the pdf page numbers (duh!)
the hatch looks like a number 3 on that page as I said there is a joint about 50mm out paralell to the hatch and at least 6 screws/bolts spaced around the hatch
 
It would be very difficult to take a photograph - its right under the M/h and getting enough space between camera and hatch would be all but impossible but certainly in the first resort I am going to try a spray of 'spray and seal' and see how that goes, Im not a big fan of lying under things getting cold and wet and its dollars to doughnuts that at least one of the screws/bolts will be a real pig to get undone and its not in the best of places to work at.

So I shall give it a spray and if that doesnt work I will bite the bullet and strip it down for a proper repair