72 Dart 225 ci.
Found coolant in my floorboard today. Question....That means my heater core is shot, right? Question#2....Is it possible to bypass the core temorarily, so as to continue driving without a heater until I can get it replaced? Anybody know where to get some instructions on this job? Thanks much

Yes, you can bypass the heater core.
Check of the hose is leaking where it connects to the heater core. Sometimes a hose leak there can run through the firewall making you think the heater core is leaking.
Is your car heater-only or does it have factory air conditioning?

The heater only is easiest. You remove the whole heater box from the car. Reach up inside the right vent to unscrew the nut on the J-bolt. the J-bolt hooks way up high inside there but the nut is just above the vent door in the inside. Disconnect the 2 control cables from the heater box (remove the glove box for access and vision). Then remove the wires from the resistor block on the heater box. The go out under the hood and remove the 3 nuts on the studs near and around the heater motor. Then the heater box pulls away from the firewall and I forget if you need to tilt it a certain way or not to work it out from under the dash. After you have it out of the car, pry off the clips holding the box together and open it up.

Oh, remove the heater hoses too, then flush some clean water through the heater core or gently blow it out with compressed air so you don't have antifreeze spilling on the carpet.

When you get good at this you can have the heater core out in 10 minutes -- REALLY -- I've done it.

If you have factory AC then the procedure is different.

Thanks for the reply. Checked the archives and didn't see instructions for A/C. Any help appreciated......Gary

Oh, now you tell Us (me)

Well, that's not so bad either. I have a AC car too but it's been 10 years since I had the heater core out, actually I removed the whole heater/ac box to clean out the leaves, paper towels (yea the one they left in there at the factory), and garbage that was piled up behind the AC evaporator core.

You do NOT have to remove the whole heater/ac box to change the heater core. Remove the AC vent, maybe the ashtray and glove box (don't remember about those), and maybe glove box again to let you see in there from a different angle.
In an nut shell.........
There is a section of the ac/heater box that comes off to replace the heater core. It's near the center of the car above the floor hump. Must be held on with some kind of screws. Remove the screws and control cables or vacuum hoses if needed. Then the cover comes off and you can pull out the heater core if there are no screws holding it in.
Gosh, I'll have to dig out my service manual to check up on the exact procedures but this is the basic version.

-Craig-