Questions about installing temperature sending unit

[surf]

I am getting ready to install the temp sending unit but had two questions. The Haynes manual says you need to partially drain the cooling system before removing the sending unit and then you need to put Teflon tape on the threads before installing the new unit. Is it really necessary to drain the coolant? I have read that if you apply any sealant to the threads it needs to be electrically conductive and teflon tape is not electrically conductive. Any help is greatly appreciated.

 

[Maniak]

Well, if you don't drain some fluid, it will drain when you take the old sending unit off, but not in a controlled manner. My guess is they want you to drain it into a bucket so that when you take the sending unit out you don't have it going on the ground.

As for teflon tape, I tape my sending units but I only wrap it twice. That way when installed the threads will still be able to cut through the teflon and make the connection to ground which is needed for 1 wire sending units.

~Mark

 

[surf]

Thanks for quick reply. That is exactly what I needed.