Changing temp sender unit on thermostat

[gone_left]

Hi all,

New member and first time T25 owner here. I only bought my van recently and the temp gauge has never worked. Using the wiki (which is immensely helpful) and reading other members posts I have diagnosed it as a faulty sender unit as the gauge goes all the way up when the connections are bridged or earthed. I have ordered a new sender (inc. clip and o-ring) but will I need to drain all coolant to fit the new unit or is it possible to do a quick swap over without loosing too much and then just topping up and bleeding the system?

Thanks in advance

[itchyfeet]

Yes be quick.and you should not loose more than half a cup
Just make sure you have goggles because you will be underneath and you dont want it in your eyes

New o ring every time and if you have crappy plastic clips get new also

[gone_left]

Just wanted to say thanks for the advice. Swapped the sensor over the weekend and now the gauge is working as it should.