Club126UK

Fiat 126 Chat => Fiat 126 Mechanical Problem Solving => Topic started by: elanman99 on March 14, 2016, 09:40:48 AM

Title: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on March 14, 2016, 09:40:48 AM

I am looking for a switch to replace the one that has come apart (not repairable) in my 1988 watercooled BIS.

I have looked at all the sites I can find that list/sell spare parts but cannot find any reference to this switch anywhere.

Does anyone know of a supplier?

Thanks in advance

Ian

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: ChrisRLewis on March 14, 2016, 10:54:47 AM

Not sure of a supplier?
For reference is a part number 7587677?

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: cider on March 14, 2016, 11:43:15 AM

Fiat Part No 7642553

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on March 14, 2016, 12:01:16 PM

Thanks Chris and Cider

Confusingly I now have two different part numbers. Does the Fiat number infer that I can get one easily from a Fiat dealer? I will though now search the Fiat specialist sites withe those two numbers.

I have the manual on CD but navigating it is difficult under Linux so could not find the jpg diagram you linked to. I tried copying the CD to my Windows PC but wont do that as it comes up with checksum errors. I was able to copy it to a Linux machine so dont have to wait every time the CD is accessed but as the CD is set up for windows I can only browse it as dozens JPGs.

Ian

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on March 14, 2016, 12:38:42 PM

I have tried both those numbers (as well as 'float', 'level', 'coolant' 'switch' etc) in Ricambio, Fiatclassic and Axel Gerstl but get no results.

Its not a desperate problem as it does not immobilise the car but it would be nice to know its working.

Ian

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: cider on March 14, 2016, 01:33:23 PM

Hi
The number was from the package when I fitted mine, Might pay to google the number

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: andyzeetec on March 14, 2016, 01:42:09 PM

They are as rare as rocking horse poo

By chance I got mine from ricambicinquecento after exhausting all other avenues.

Here is an old post of mine..  http://club126uk.co.uk/forum/index.php?topic=8930.msg67969#msg67969

I hope you find one!

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: 126blackbird on March 14, 2016, 09:19:05 PM

I may have a used one, will have a look tomorrow and let you know.

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on March 14, 2016, 10:02:02 PM

I looked at my faulty switch again today and now have a cunning plan!

The white plastic that the float part is made from has gone brittle with age. Its little pivot pins have snapped off and the magnet it contained is missing (I only found the float part in the header tank). I thought I would fabricate a completely new float but before doing so I tested the body part with magnet. Using ever stronger magnets I discovered that the actual (reed) switch was defunct.

I have now removed the switch and all the potting resin around it so I have an empty casing into which I will install a new reed switch. Extracting the body contents was a bit messy, as I drilled out most of the resin I found that it gets into a sticky mess as the drill heats it up. If I did another one I would heat the whole thing to about 70-80C and I would expect I would then be able to take out the whole lot by pulling the wires.

Not sure why a completely sealed in reed switch would fail in the first place, (possibly somehow got 12V put across it) but I will check the car wiring before I connect it it up.

Ian

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: Jaygrint3 on February 06, 2017, 02:20:26 PM

Hi Ian.

I was just wondering how you got on with the issue.
I've got the same problem as my switch 7642553 doesn't work. Taken it out gave it a good clean but still no good.
It's all in one piece nothing broken so I guess the magnet in the reed part is faulty

Thanks

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on February 06, 2017, 10:00:15 PM

I spent quite a while repairing my broken switch but I cannot say I succeeded.

I dug out all the old potting and the already broken reed switch. I made a new swinging arm into which I fitted a small magnet and fastened the old foam? float to. I tested its operation before I potted both parts (so the magnet would not corrode) and was happy that it still worked OK after it had all cured.

Fitting it to the tank did not go well, I had got the proportions of the swinging arm wrong so it would not pivot once it was inside the neck of tank aperture. I remade the moving are two more times and I know it now works.

For some reason when I fill with coolant the switch does not change state. I confused myself a few times trying to work out if the switch was meant to open or close as the level rose. At the moment the light is on all the time but the car is not in use at the moment but I will look at it again when the weather warms up.

I will see if I can post some pictures of what I did.

Ian

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: Jaygrint3 on February 08, 2017, 05:21:50 PM

Blimey. That sounds like a massive investment of time but I can see why because there just aren't any anywhere to buy.

I'd be interested to see and hear how you get on.

Thanks for your reply.

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: andyzeetec on February 27, 2017, 08:55:03 PM

How about this place..

https://translate.google.co.uk/translate?sl=auto&tl=en&u=http%3A//autoricambifirat.it/shop/index.php%3Fmain_page%3Dproduct_info%26cPath%3D1_273_382%26products_id%3D6220

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: elanman99 on February 27, 2017, 09:29:20 PM

That look a good find and a good price for something that seemed to be unobtainable.

I'm tempted to buy one but slightly wary and I wondered if anyone here has used them?

They show the price as VAT included but I suspect that by the time postage (and custom duty?) will bump up the price by the time it gets to my letterbox.

Ian

 

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: Xylaquin on February 28, 2017, 04:06:22 PM

If you have the part number, use http://en.partacus.de

Title: Re: Float switch in coolant header tank (126 BIS)
Post by: andyzeetec on February 28, 2022, 06:56:09 PM

If anyone needs one, pricey though, as rare as rocking horse poo .

https://www.ebay.co.uk/itm/Sensor-Bowl-Radiator-Fiat-126-Bis-Cod-7642553-New-Original-/255403479852?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0