1973 Eldorado Ported Vacuum Switch Quick Question

Started by SaltLife97, December 10, 2021, 04:13:35 PM

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SaltLife97

It appears as though what Cadillac called the Thermal Vacuum Switch has snapped off previously on my engine and of course no one in the past has replaced it. RockAuto doesn't list (nor does anywhere else) the part until you go into the 1976 Eldorado year. Oddly enough, the 1976 shop manual does not mention anything about a ported vacuum switch under the cooling system or fuel section. It appears all three ports are there, I'm wondering if it is okay to use? Only criteria is that the switch activates and switches vacuum source when coolant reaches 220 degrees as per the 1973 shop manual.

"Cadillac Kid" Greg Surfas 15364

What is a ported vacuum switch on the earlier motors is the "EFE" (early fuel evaporation") cpontrol on the 76.  The ported vacuum switch on your car opens the vacuum passage to manifold vacuum at 230 degrees while the EFE valve closes the vacuum to the heat riser valve at 150 degrees. Quite different. I still have a couple of NOS and used thermal vacuum witches so if you need one PM me.
Thanks
Greg Surfas 
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

SaltLife97

Quote from: "Cadillac Kid"  Greg Surfas 15364 on December 10, 2021, 04:24:13 PM
What is a ported vacuum switch on the earlier motors is the "EFE" (early fuel evaporation") cpontrol on the 76.  The ported vacuum switch on your car opens the vacuum passage to manifold vacuum at 230 degrees while the EFE valve closes the vacuum to the heat riser valve at 150 degrees. Quite different. I still have a couple of NOS and used thermal vacuum witches so if you need one PM me.
Thanks
Greg Surfas

Quite the difference indeed! Thank you, I sent you a pm!!

Kristof