1968 Still over heating

[green56]

I have a dumb question when i start the car and let it run for about 5 to 10 minutes the water comes out the over flow now i check the level in rad it was just below the neck of the rad now when i checkl it is just above the tubes is this OK or this should not happen i will probably will have to add some water need help

 

[franklinair]

After running for such a short time, I'm surprised anything comes out the overflow. Seems to me the engine (and coolant) would take longer to warm up. What pressure is the radiator cap? I would think it would take longer to build up 14 to 17 PSI in the cooling system.

Neil

 

[CougarCJ]

Let the radiator find its own level. Just below the filler neck is too much coolant.

 

[robert campbell]

I spent a few years working in a radiator shop. Scott is right on!! A 1960's closed system with no overflow tank should not be filled to the "brim" so to speak. Most will find their own level which is an inch or so under the filler. You will get the feel after a bit and once in a while a small amount may be added.

If you keep the water right to the top some over flow will occur. I have seen instances where a closed system completely full with no expansion area in the top tank water can actually “bulge” the top tank. Normally a truck pulling a trailer and working hard. Or if you romp on your stang real good in the same situation.

The air in the top tank can compress and compensate for this sudden surge. Yes, the cap is designed to release pressure, but not quick enough in this hydraulic situation.

Never fill to the brim! Leave some air space.

Rob

 

[green56]

over heating

the rad cap is 14lb 0ok will leave it to seek its own level thanks Guys