Overheating problem on the 440, with a strange twist??

[71 RT]

I have searched the previous posts concerning this issue and do not see anything like this topic.  I hope someone can help!

I have a strange problem with my radiator/radiator cap and overflow tube.  If I fill my radiator up to near the top and put my radiator cap on, once I start the car almost immediately water starts comming out the overflow tube on to the floor.  It is not all of the water, just about 12-18 ounces, then it stops.  The car runs on the warm side, but never pegs out all the way.  I just can not figure out why it puts some water on the floor, then stops.  I have replaced the radiator cap (16 pounds) and have rodded the radiator.  Anyone else out there have a clue? 
Thanks for your time.

[myk]

That excess should be flowing into a catch-can or reservoir.  The motor will pull that excess coolant back into itself if it needs it...

[dodge freak]

Yes if there is no catch can or over fill bottle only fill up the rad 1-2 " to the top. This is how the cars were till the early 70's.

[4402tuff4u]

My 68 was doing that and my mechanic said that I had to leave some space for heat expansion. You should just have to fill it approx 1" below where the cap seals with the radiator, that's if you dont have a reservoir.  If you have a reservoir as stated above, the rad will intake and/or release coolant as needed.

[Chryco Psycho]

iuf you have the stock rad you wil see a plate soldered into the rad directly below the rad cap this is the fill line , if you fill above that the heat expansion will push it out

[71 RT]

Thanks fellas!  Lots of good advise.  My car did not have a reservoir.  I will try leaving it down a bit.  Thanks again fro your time.

[resq302]

iuf you have the stock rad you wil see a plate soldered into the rad directly below the rad cap this is the fill line , if you fill above that the heat expansion will push it out

Ah is that what that plate is inside the rad.  I always thought that was a baffle so the coolant woudnt splash out the filler neck if you had the rad cap off.

[daytonalo]

Don't assume your car runs hot until you use a digital inferred on you rad, engine and upper and lower hose ! I just restored a 69 AMX for a customer and the jackass insisted the car was running hot because of a slow crank problem , I new better and showed him I set up his car to run 150 all day long . Do your homework !