How full should the radiator be? 351 C

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kcmash

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Silly question, but I forget how full the radiator should be.  When I look down the fill opening there is a tube standing about 2/3 of the way up toward the cap.  My coolant level is about 4 inches below that.

The last time I was out I was trying to adjust the timing.  I had been driving about 20 minutes and stopped to make an adjustment. I turned the car off for a couple minutes then started it to head out again.  Some spectators commented that I was loosing fluid.  When I checked the temp gage, it was all the way to the hot side.  I sat for about 20 minutes then decided to drive for home.  As I took off the temp went from 3/4 to high on the temp then finally started cooling and came down into the lower 1/3 of the gage for the rest of the trip home.

So with no overflow reservoir I am concerned about running my fluid too low, and also concerned about over filling it.

What is the correct coolant level?

kcmash

 

6DUB606

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On the side, just below the cap, should be the words " cold fill " or something similar.  May depend on the radiator you have if not original or good repro.

Either way, if you overfill it, the surplus will be spat out when it's at running temp.  Any more than that may suggest a problem but don't over-react until you check further.  The temp gauge will certainly show high at next start up if its been sitting and then settle back as the coolant flows again & fan is running.

PKJ

 

kcmash

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It is an original radiator.  I forgot about the stamping on the side of the radiator.  Thanks.
 

Yep I figure a 300 to 500 mile engine will be running warm too.

kcmash

 

timachone

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KCMash, 

I have the original rad too and my coolant level has leveled itself at about a little less than an inch over the inner tube of the coolant reservoir. 4 inches below that tube seems a little bit too less for me... 

 
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If I look into my rad, factory tanks, but 3 core, the level is about 2" down cold. I'd fill it to about that level and keep an eye on it, If it goes any lower, go got a problem!

 
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