The old sensor put the needle in the centre, then new one puts it near the red, I went to put the old one back in and it just fell apart in my hands (be carful not to over tighten  

 ) so am still using the new GSF one. I was fault diagnosing the red flashing LED that wouldn't stop flashing! (turned out to be the PCB in the dash, I replaced the complete dash dial set inc. spanking new clock from a German trader at Busfest 

 )
I'm not hi jacking the thread...just if you change your temp switch.....
P.S 
I'm sure I haven't got any trapped air....although some may say otherwise... 
 
  
1984 Marsala Red Pop Top Westy.