Strange - fresh water level sensor broken

[bvirc]

For a while I was wathcing my fresh water level indicator not working properly. My VW service shop was blaming limescale, but it was an epic journey to open the lid of the tank - I didn't allow to use a brute force and demanded to order a special opening tool provided by VW.
After finally opening the tank today there was a surprise - the sensor is multiple cracked. I obviously need to order a new one. However, I am wondering what was the cause of it - water in the tank never froze and there is no other physical stress present. Any idea?

 

[bvirc]

The indicator / sensor worked perfectly for 3 years, I noticed a malfunction during last winter, so I am almost sure that low temperatures somehow caused that.

 

[2CV67]

I had the same problem & also believe it never froze.
If getting a new part, make sure you get the newer stainless teel one & not the outdated plastic one!

 

[grainflow]

Hi, has anyone got the part number for a new float sensor handy? I've searched a few threads and can't seen to find it,

Thanks in advance..

 

[AlisonF]

Hi, has anyone got the part number for a new float sensor handy? I've searched a few threads and can't seen to find it,

Thanks in advance..

@WelshGas may beable to help.

 

[Pineweasel]

Hi, has anyone got the part number for a new float sensor handy? I've searched a few threads and can't seen to find it,

Thanks in advance..

7E7 068 257B

 

[Shacko]

7E7 068 257B

That’s great, I think I need one too. Can anybody enlighten me as to the tool required to open the tank, or how to improvise one?

 

[westfalia]

That’s great, I think I need one too. Can anybody enlighten me as to the tool required to open the tank, or how to improvise one?

Something like this -

 

[westfalia]

Something like this -
View attachment 76785

Although i got mine off with these-

 

[westfalia]

Don‘t mind @westfalia his dodgy tools
Read this thread and find the perfect tool

Removing lid of water tank to clean it

So it's the big one, not the small one. I've been doing it all wrong then...

vwcaliforniaclub.com

post #34 , don’t know if the forumshop still has them in stock , check out here

Shop Home - CampervanBits

Campervanbits - Accessories and Parts for VW California, California Grand, Marco Polo and VW T5, T6 and T6.1 Campervans.

vwcaliforniaclub.com

Ha ha, I would rather improvise than buy a tool for
a once in a lifetime use

Once you have the lid open then its best not to tighten the
life out of it when putting it back, you can then always release it
with your thumbs if you don't have any thumbs, index fingers will do
the job just as well.

 

[Shacko]

Oooh, decisions decisions. I think I will try improvising. Then buy the tool from the shop . Thanks all

 

[WelshGas]

Oooh, decisions decisions. I think I will try improvising. Then buy the tool from the shop . Thanks all

a length of wood or metal with 2 bolts positioned apart 2 cms or so less than the diameter of the lid will do it.

 

[Shacko]

Thanks all. I made a tool, as suggested. Bolts 10cm apart. Got the failed sensor out easily and was surprised to find it is of the stainless steel type. It seemed to have failed due to corrosion at the lower end.

 

[ArunAlec]

Does the split in the plastic have an affect on the operation of the gauge? I’d assumed the electrical “element“ was probably encased and watertight with a plastic sleeve for the smooth movement of the float. Whilst changing my water pump I noticed my tube was split. My water level readings have always been rubbish!

 

[Shacko]

Yes I’m sure the split in the plastic ones is what causes them to fail when water reaches the internal components. Hence the newer version is stainless steel. However the one that failed in my van was in fact a stainless one, which had corroded at the bottom join.

 

[steve_b]

Does the split in the plastic have an affect on the operation of the gauge? I’d assumed the electrical “element“ was probably encased and watertight with a plastic sleeve for the smooth movement of the float. Whilst changing my water pump I noticed my tube was split. My water level readings have always been rubbish!

Yes. I have pictures of mine that I cracked apart (yet have time to post, nor try and create a better fix). The very simple electronics are cased in some kind of rubber or silicone but the rust on the little magnets by each reed switch tells me that it is imperfect.

I expect in my case the problem may be the tiny magnets used to bias the reed switches perhaps becoming more or less magnetised so losing the latch as the magnet moves past. Similar issue to the hall sensors used for the roof maybe

 

[ArunAlec]

Yes. I have pictures of mine that I cracked apart (yet have time to post, nor try and create a better fix). The very simple electronics are cased in some kind of rubber or silicone but the rust on the little magnets by each reed switch tells me that it is imperfect.

I expect in my case the problem may be the tiny magnets used to bias the reed switches perhaps becoming more or less magnetised so losing the latch as the magnet moves past. Similar issue to the hall sensors used for the roof maybe

As I’m currently on bit of roll with minor repairs I might change mine for a stainless and do an autopsy on the cracked one.

 

[steve_b]

How it works is pretty simple from an electrical point of view, it's only 2 wires, all passive and a simple resistance change as the magnet passes each float.
In mine the reed switch wasn't latching as the float passed it, so the resistance ended up being illogical. I am tempted to replace it with 2 X float sensors from eBay for 5 quid and a couple of resistors
Or you could go cheap option , drill a hole in the lid and insert a wooden spoon handle. Remove spoon and see how wet the handle is.

 

[gurik]

Děkuji všem. Vytvořil jsem nástroj, jak bylo navrženo. Šrouby od sebe vzdálené 10 cm. Snadno vytáhl vadný senzor a byl překvapen, že je z nerezové oceli. Zdálo se, že selhal kvůli korozi na dolním konci.

Děkuji všem. Vytvořil jsem nástroj, jak bylo navrženo. Šrouby od sebe vzdálené 10 cm. Snadno vytáhl vadný senzor a byl překvapen, že je z nerezové oceli. Zdálo se, že selhal kvůli korozi na dolním konci.

View attachment 81623

My senzor wrong on my T6.1 2020 too