Help please leaking red seal under van

Went to Willersey 4 days ago to sort problem.  Waited 4 days to test seal, OK with small amount of water but  under pressure with more water it is still leaking.  300 miles round trip to Willersey and off on hols to Spain in 9 days.  Any ideas please?

What red seal?  Sorry but a bit more info needed.

Sorry, it’s a red cap to the water tank in the middle of van underneath.

It sounds like you have a leak from the seal on the inspection cover on the bottom of the Fresh Water tank. Did they replace this seal with a new one ? if so have you tried to tighten the cap a bit more.
After I had my tank cap off it wouldn't reseal as the rubber gasket had gone very out of shape but a new gasket fixed it.
Perhaps you could ask Autosleeper to post a new seal to you and get it fitted locally.

Thank you for your reply. No they didn’t fit a new seal and reused the same one.  Have tried to tighten it, but it didn’t move. Looks like we will be driving over on Monday and staying on the Broadway site and turning up at 8.00 am ( there is no answephone) and hoping they can sort the problem on the Tuesday. Unfortunately all the local seem to be full up with hab checks.

I would suggest phoning first, perhaps the reason that they didn't fit a new seal is because they hadn't got the correct seal in stock, I know that they are not all the same size and shape.
My tank has a part number on the bottom and I obtained a seal from the  tank manufacturer.
If you raise the van on levelling blocks it really is only a 5 minute job.

Good luck

Thank you for your help, in hindsight we should have had a new seal, especially all the effort in getting there (M25/M40), accidents, roadworks (9 hours travelling).  We don’t have a lot of room to manoeuvre on the drive, unfortunately we don’t have an option but to go back to Willersey.

Non setting builders' sealant.

Wrench off the red cap (they always do them up far too tight!) and slather plenty of sealant around the seal and in its locating grooves. Tighten it back on with a bit less muscle in case it has to come off again.

It's not rocket science, and it will either continue to leak or it won't. If you drink from the tank (as we do) you may prefer to use something like vaseline. It also has the advantage of making the cap far easier to unscrew in future, and although it may not be as effective if your seal is badly damaged, it should work perfectly well if it's still in reasonable condition.

When we had an inspection hole under the tank (halcyon days - the miserable tightwads don't fit them now!!) vaseline worked fine for more than two years until we sold the van. Probably still OK now!

Hope this helps.

Thanks Dave, the other half is under the van now to see if he can unscrew the red cap.  Being a woman I thought it strange that we had to wait 48 hours to test the cap, me thinking that perhaps the sealant that was used had gone off?  Will try the Vaseline if he gets the cap off.  He is checking the screws to make sure that they are holding and the threads are OK.

That sounds to me as if they removed the cap flange and re-sealed that against the body of the tank. Hence the curing period for the sealant.

If it turns out the leak is from there, rather from the cap seal, clean off the edges of the flange and the adjacent tank surface as well as you can. Roughing it up a bit would help too. Then "finger" in a bead of Sikaflex all the way round. That does need 24 hours to cure, but once set it sticks like you-know-what to a new blanket!!! 

I certainly wouldn't contemplate the long journey back to Willersey. At worst your husband undoes the screws and gets the flange off - using cheese wire to cut the seal if necessary. Clean off and reseal with lots of Sikaflex, then you know it can only be the big "O" ring seal under the red cap. Half a jar of vaseline should cure that, specially if you give the screw threads a liberal dose as well.

Fingers crossed!  The Vaseline is working! Thank you so much Dave for your advice and I think we will invest in a spare “0” ring and Sikaflex.  Perhaps, Willersey AS will send us a spare “0” ring? This may seem an obvious question but were we supposed to drain the water using the red cap?  We did open all valves/ drain taps etc as stated by everyone.

Spokes wrote:Fingers crossed!  The Vaseline is working! Thank you so much Dave for your advice and I think we will invest in a spare “0” ring and Sikaflex.  Perhaps, Willersey AS will send us a spare “0” ring? This may seem an obvious question but were we supposed to drain the water using the red cap?  We did open all valves/ drain taps etc as stated by everyone.

Don't invest in Sikaflex until you need some. It has a fairly short shelf life and goes solid in a few months, and at about £8 a tube you don't want to waste it like that.

No, you drained correctly by opening the tap. The red cap is purely for inspection. That really means cleaning if you want to scrub the inside of the tank from time to time. Frankly I wouldn't bother unless you have reason to believe it's contaminated. As I said before, A/S don't fit them (on Nuevos anyway) any longer, so I can't scrub my tank even if I wanted to.

Afternoon spokes
I had the same problem with the tank on our sigma 
I found it started dripping for no apparent reason and olso found it hard to remove the red cape 
I made up a big spacer out of a piece of borde by cutting a wide slot in the side of the bord to fit the cape
and use as a leaver
My tank was leaking from the flange witch was held on with ten self taping screws 
On trying to titen them thay just kept turning 
I ended up taking the tank off so I could clean it and re seal all the pipe fittings at the same time
But you don't need to if you can get at it
I drilled five mm holes in between the existing screws and then removed the screws and drilled those holes 
You need to drill near the outside of the flang so the cap don't hit the bolts 
The sealants was broken down  you nead to mark the flang as it a Paine trying to lineup the holes again 
Went toToolstation and brought m5  16 mm stainless steel bolts and nuts part no 32362 and12051
And a mastic adhesive rarther than a sealant  toolstation puraflex 40 part no 85566  cleaned everything and re bedid the flang  
 I was a iot happier with twenty bolts holding the flang on then the screws  hope this helps
Jim

Join the club!
Mine (on Nuevo) leaks too!  considered having a go at fixing it myself but Im old its cold and I wasnt for climbing under the motorhome having all sorts of muck falling down on me.
any way its just back from the caravan repairers who have had their FOURTH go at fixing it - guess what? it still leaks! not as much as it did but still a definite drip!

Great to know that some of us are still motorhoming aged 98, Spokes. Gives us hope for the future. 

Liz

Sorry, not you, Spokes, I meant Spanner!
Liz

Many of the tanks in UK built motorhomes are made by CAK Tanks in Kenilworth. It might be worth giving them a ring and asking if they can supply a new seal if AS can’t. I took the bottom cap off mine to fit a tank heater. I used Super Lube synthetic grease to lubricate the seal and thread when I put it back and it sealed perfectly.

ajrm, thank you for your advice and will certainly bear that in mind.  Fingers crossed no leaks since we took bottom cap off and spread Vaseline liberally around the seal, and didn’t over tighten the cap.  A/S have kindly sent us a replacement flange plus cap, just in case. Thank you to all forum members who gave us advice and hopefully it will help others who may experience the same problem.