Classic/Antique Car Repair/Packard radiator


I have a '40 Packard Super 8 that has a tendency to lose coolant through the overflow tube after the car is driven any distance.  The car does not have an overflow tank.  After this occurs, the coolant level in radiator recedes below the filler neck.  Is it just seeking its own level, or should I continue to refill it to an inch below the radiator cap seat?

The most common causes are over filling, defective radiator cap and engine running hot. Remember that when you shut the engine off after running a while the temperature will spike and this could cause some boiling. The pressure cap is supposed to raise the boiling point of the coolant and prevent the spill over. Most of the time over filling while vent out of the overflow tube while you are running down the road. I would either replace the pressure cap or have it tested.  

Classic/Antique Car Repair

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Brad Sears


All automotive including antique and collectible. However if the car has been modified I can only answer in general terms and maybe get you pointed in the right direction.


Automotive tech instructor. Syndicated auto columnist 1970's though the early 1990's. Syndicated auto radio talk show, Ask Brad About cars, CBS Radio 70's through 90's TV Show "Last Chance Garage" 1980's PBS-TV syndicated. Auto instructor for the following companies: Fram Autolyte Holly Carter AMF Ford Motor University Of Conn Blue Hills Technical School Sugar River Technical Center Grew up in a family garage in Needham Mass and turned wrenches from the age of 14.

Manchester Union Leader, Nashua Telegraph, Motor Service Magazine, Yankee Magazine, Popular Mechanics (Saturday Mechanic early 80's), Los Angeles Times, New York Times, and lots more.

More than I care to remember. Basically Franklin Technical Institute in Boston, Northeastern University, Fitchburg State Teachers College, Tufts University, and a lot of factory schools along the way.

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Moto Award winner. And much more.

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