71 Cuda overflows flows after driving...

[Sarsmopars]

I have a 71 Cuda 340.  It runs great, idles fine, shifts normal.  Temperature is good while driving (180 degree gauge) but as soon as I shut it off it overflows.  I've replaced the lower rad hose (with spring), thermostat and clutch fan but it is still overflowing.  Any ideas??

[roadman5312]

Radiator cap.       

[dfrazz]

Radiator cap.       

   You need a good pressurized cap.  Also, if you keep filling it up it will overflow the excess that it doesn't need, so try not to put any additional coolant in and run it to see if it still overflows.

[Katfish]

Probably filling the radiator to the top?
Should be 1" below the cap.

[tman]

If you want to make your own coolant recovery system and want to maintain a stock look, its pretty easy.  Just use your windshield washer tank, but it has to be a manual one.  Otherwise, you change it to manual and need some hoses and correct radiator cap for closed system.  Then you can fill the radiator to the top.  Or to keep it stock, don't fill to the top as mentioned earlier. 

[YellowThumper]

Yes, don't fill to the top as mentioned. I also had similar issue when the radiator was bad with many of the cores were plugged up. After engine warmed and thermostat opened the pressurized water would try to circulate and couldnt so it would blow out. Took awhile to understand because car was not overheated but then would.

Good luck
Mike.