oil/temp sending units

[bear76]

When changing the temp. sending unit do you have to drain the coolant? Same question for the oil pressure sending unit.

Thanks

 

[dyeager535]

Coolant temp will drain, oil pressure will leak some, but not much, essentially all the oil goes back to the pan.

You can try siphoning coolant out of the radiator, if you get the radiator level lower than the coolant temp sender you may actually get some to drain away from the heads.

 

[bear76]

Thanks.

 

[4xcrazy]

but then again, if you have the new temp sender right next to you, and your quick enough and ready, you can swap them with little coolant loss

 

[bear76]

...

 

[bluehen]

I didn't drain either when I replaced them.