Okay this is not necessary a Mustang question sorry. But I figured I would ask here because its a classic car. Was the coolant back then 50/50 meaning 50% water and 50% coolant? Was there anything different about coolant back in the 60s?
I am working on my grandfathers 69 Jaguar 4.2L E type series 2 and I got it running and put in regular 50/50 coolant. Now there seems to be a lot of steam/vapor shooting out the overflow hose. I put in the correct amount. Figured I would ask because I am not apart of a Jaguar forum haha.

 

50/50 means 50% antifreeze.

Sounds like you need a new radiator cap

 

Okay my grandfathers mechanic changed the cap but he put on the 7lb cap and it should have been 13lb. I replaced it. The coolant still boils(literally I can hear it boiling in the reservior). The fans that are supposed to cool the radiator do not turn on. They are electric. So I will check them out later today when it isnt 95 outside. If anyone has any other suggestions I am all ears .
Thanks James.

 

Bleed (burp) the cooling system to let out all the traped and expanding air.

 

You also need to get an accurate temp reading of the cooling system. An infrared thermometer is handy, but you can also tape a mechanical thermometer to the radiator.

 

bleep or blurp the radiator? how do you do that?
star i already did that. its really really hot hahaha.

 

The bubbling is definitely the coolant boiling. If it's a 50/50 mix it boils at 225 degrees with no pressure cap, even higher with one. You have to get those fans working.

 

okay so I bleeded the coolant. got some air bubbles out of it. the temperature raises a lot slower now. I still can not seem to get the fans going. looking into it tomorrow. might need to get new ones. the motors on the fans might be blown. they are electric

 

ditto on the fans,,they are a must have

 

Try connecting them directly, then you'll know if is the fan motor or the thermal switch.