Cadillac Seville / Cadillac Eldorado Forum Discussion, Losing coolant, no visible leaks.... long description in Past Cadillac Vehicle Discussion; Originally Posted by Submariner409
You have said there IS a coolant surge tank, that the "radiator cap" is not on ...
Re: Losing coolant, no visible leaks.... long description
Originally Posted by Submariner409
You have said there IS a coolant surge tank, that the "radiator cap" is not on the radiator itself.
The proper level of coolant in that surge tank is half full, cold. The surge tank is part of the pressurized system - there is no "coolant overflow bottle" or "coolant expansion bottle" as in older, obsolete coolant recovery systems.
You overfill that surge tank, and as the coolant expands normally during warmup, it WILL bleed off coolant. Half full, cold.
Is there a legend molded into the top/side of the surge tank "FULL COLD" with a flat line/arrow going over and down the side to about the mid-seam ???
200 degrees running temp is perfect - right in the midle of the desired 188 - 210 range.
Zoom in on this page from the 2002 service manual - the surge tank - see the number 1 and line to the tank mid-seam ??? That's the proper cold fill level. (The Note on supplements is deleted and obsolete)
Also note some Eldorados (like mine) have an opaque black surge tank so use best judgement.