Oops!
I have managed to break one of the wires on my coolant expansion tank. Its broken right up at the tank, with no chance of reconnecting it. Is there some way of stripping it down to replace the wiring, or will I need a replacement tank?

- (#8405) dave Bright, 12 May 03 1:59

Dave. This happened to me also but, if you take the tank out, you should find that you can solder a short brass pin into the broken terminal,(a piece of stout copper wire would do) and then solder a new wire onto that. A blob of Araldite would also secure it's location. This is what I did a couple of years ago and it has been fine ever since. As an extra, I put a cable tie round the bottom boss of the tank and secured the new wire onto the side of the boss. This takes any tension off the wire which, in my opinion, is the reason they break in the first place.

- (#8406) John Davis, 12 May 03 2:10

As John says, the float switch will come out of the tank, then you can lever the bottom plastic cover off (that the wires go through) to get into the switch itself

- (#8407) david miller, 12 May 03 3:26

Thank you for your very helpful advice John and Dave.

I did think of trying to remove the float switch, but I wasn’t sure if it was possible without breaking any seals or something. Forcing a bit of copper wire into the hole sounds like a good Idea, so I will start with that. If I am feeling brave one day, I will strip it down.

- (#8408) dave Bright, 12 May 03 4:18

David refers to a float switch but my '91 Townace has a unit with a resistor and a glass-encapsulated heat-sensitive switch. It looks as if the resistor is supposed to heat up the switch to cause it to open when there is no coolant around it to absorb heat. However mine doesn't work beacuse the switch is already open, even after freezing it. I check the coolant visually every two weeks or so anyway, but any help fixing it would be welcome.

I found this out when I was fixing the same broken wire situation. I don't know about float switches, but the resistor/switch assembly slides into a dry chanber in the bottom of the tank. No problem about making the tank leak. Around the base are plastic lugs which I softened with a soldering iron to release the switch etc and to hold it back in afterwards. Given that the tank simply pulls up out of the car, it's a very easy job to tackle.

- (#8452) Dave Mason, 12 May 03 8:33

It's just dawned on me, pondering this thread, that my explanation of my u/s switch may be rubbish and that I should have a float with a magnet that operates the switch. Does the float simply slide up the chamber that contains the switch? - mine must have slid right off.

- (#8472) Dave Mason, 12 May 03 10:04

float slides up and down inside the switch housing. The reed switch is concentric with it. If you remove the switch from the bottom of the tank and give it a good shake in fresh water, you'll find a load of crud will flush from INSIDE the float chamber. (the outer tube can unclip got cleaning if you're careful)
The float should rattle around loose in it...

- (#8473) david miller, 12 May 03 10:24

Having just noticed a slight dripping of coolant from the gearbox bell housing, I thought I had better get the float switch fixed, before tooling of to Aylesbury this weekend. It stripped out, just as John and Dave Miller said, and now I have a working “Low coolant” warning light again.

Whilst I was fixing it, I noticed that the switch appears to be pole oriented. The plastic base has two grooves on one side, and only one on the other side. So perhaps Dave Mason’s broken float, might just be because the switch is not in the right place, or perhaps the plastic base has been reversed?
Thanks for your help chaps.
dave Bright.

- (#9473) dave Bright, 4 Jul 03 6:43