The problem I am having is there is a small amount of coolant on the floor  behind the front right wheel area of my 1969 427 with a/c .  I had the heater core and hot water valve replaced. Could it be a heater hose loose? Is my coolant system too full and it blew out when the engine got hot?  What is the correct level for the coolant in the expansion tank?  It is the long style tank. Thanks, Bob

Depends...can you tell if the leak is dripping straight down, or is it running down the frame, and dripping off there?
A leak in that area would certainly suggest a heater core/hose leak, but...it could also be the overflow tank leaking, and running down the frame until it gets to the lowest part of the frame, which happens to be right where you see the coolant on the floor.

I have checked under the car and see that the coolant is leaking down from some area and collecting under the frame and then dripping on the floor. It is a small amount. The expansion tank is in good shape, no signs of leaks. hoses look good and tight.The level of coolant  in the tank is about half way. What is the correct level?

Sounds like the leak is probably from a heater hose...perhaps when the core was installed, the clamps were not tightened enough. Hopefully it is not the new core leaking. Might take a mirror and a light to look up in and around the hoses and get a better look.

As far as the level in the tank, I think 1/2 full is correct, but I do not know for sure. Perhaps someone here with an Owner's Manual could look and see what the proper level is.

Thanks, I will take another look at the hoses. Hopefully it is just an overfilled tank that has overflowed . The level cold is about 1/2 way down.  I will monitor the leak. I can take it back to the mechanic if it does not get better.

do you see this leak each time you drive your car? Have you started it and let it run and watched for the drip to appear? Does it only leak after its turned off and it sits? I have seen many cars that will only leak after they run and are turned off during the cool down they may drip. My guess would be a hose needs tightened but it could also be that the new valve could leak. Sounds as tho your going to have to start it up and spend time checking it until you narrow it down. I think you will be ok as far as the heater core since the leak is outside the car to the floor.
Good luck and let us know what you find.
Rodney

Pressure test the system...that should tell you where the leak is coming from.

Finally got the car to my mechanic and he found a hose clamp loose on one hose going to the heater core. I will monitor the area and hope the problem is fixed.