Bill,

I used the same float switch as Al and couldn’t find it on McMaster’s site either.  They do carry some others that should work, but pay close attention to max operating temperature.  Some are good to 300*F, others much less. 

 

 I were to do it again I think I would use one of those I/C’s that Ed Anderson mentioned a while back that were being offered on ebay for pennies each.  Auto manufacturers use them for liquid level monitoring.  Maybe someone has the p/n handy.  I don’t have it, but I could look it up tonight.  One wire to the tank senses fluid level.  Very light weight and high on the coolness scale.

 

Mark S.    

 

 

Subject: [FlyRotary] Re: Radiator Expansion Tank

 

Bill Schertz

Bill;

 

I got the sensor from Mcmaster-Carr, but I am unable to find my receipt, and looking on their web site I was not able to find it.  Apparently they no longer carry it.  It mounts in horizontally, but has a 90 degree bend and magnet/float that moves vertically.  It is a magnetic reed switch, made of blue nylon good to 300+ F.

 

Sorry can’t be more specific.

 

Al