So I thought my 96 Accord was leaking coolant. It seemed like every time I checked it which would be before driving it each time the coolant would be low. Or at least I couldn't see it from pulling the radiator cap off. Anyway, I haven't had time to look for a leak so I've been just adding anti freeze before driving. Now I notice that the overflow tank is almost full of antifreeze but once again it looks low in the radiator. It seems like it's not leaking out but all going into the overflow tank and not staying in the radiator. Any idea's what's going on here?

 

Take the cap off when cold, fill radiator, start engine with cap off and look for bubbles, could be a leaking head gasket, i have had this twice on my 92 and 93, if no bubbles are present look for leaks, probly none. I know this is not what you want to hear, sorry
Frank Allen

 

So why is it leaking into the overflow tank? Is this what the head gasket usually does? Wouldn't I also see other signs like of it getting hot or something?

 

Sounds like the overflow system isn't working correctly. With a properly functioning system, the radiator will be full to the top when you remove the cap. As the coolant and entrained air heat up, they expand and push coolant (and air) into the overflow tank where the coolant sits in the bottom and the air is vented out the lid. After shutting down, the coolant contracts, creating a vacuum that pulls coolant in from the bottom of the overflow tank.

If there is a small leak in the radiator outer cap seal, or in the tube to the overflow tank, it will pull air back in to the radiator instead of coolant from the overflow tank.

If the tube in the overflow tank has fallen off (or is missing), the same thing will happen, it will just pull air from the top of the tank instead of coolant from the bottom.

Just reread first and third posts. If you really see no coolant at all when you remove the cap, it may be the head gasket. Compression and combustion pressures are higher than cooling system pressure, so leakage into the cooling system will tend to push air and coolant into the overflow tank (more so than normal heating/cooling exchange). Is there evidence that coolant is overflowing the overflow tank? The head leak (if leaking) would potentially allow the system to pull air in through there when cooling instead of coolant from the tank.