Forgive the photo, but on my way back to work from my lunch, I was horrified to see "smoke" coming from the engine as I was about to park.

I was somewhat relieved to see that it was only steam from the hot fluid in the cold air. There's a small cut in the hose (not easy to see in the pic, but its there), just left of the dipstick that was the culprit. Could you guys confirm that this is standard heater hose, and of what size? If I'm lucky, the hose will have enough slack I can cut it shorter and reattach it for now, put some new coolant in and maybe have her running to get home tonight.

I was able to shorten the hose and bypass the break, but on the drive home it reached 250 degrees so I'm guessing I'll be needing *even* more coolant.

Looks like the original braided heater hoses to me. I can't tell what exactly is leaking in your picture, is it the little short reducer piece thats about 3" long? I was able to get away with replacing that with a short piece of regular hose in a sort of inbetween size and some judicious hoseclamping, I forget the diameter. As far as the heater core hoses that penetrate the firewall, I suggest special ordering those from motorsport auto as they have some crazy pre-bends in them that'll just kink if you try and use regular bulk hose.

1. When you lose a hose, typically you will get air in the cooling system. If you don't burp the system, the air will cause you to overheat.

2. If you lose a hose going to the heater core, you will need to block off both hoses. Looping the system will cause the hot coolant to recirculate.

Im not sure I understand your second point, steve. Am I not supposed to burp the system if its the heater core hose? Its in the long pre bent heater hose that goes through the firewall. The break was in the fist inch of hose, so I was able to cut out the break and reattach it. Saving it for now. Youre correct. It is indeed the original braided hosing. Not the first bit thats been giving me trouble, either. Thats what 40 year old hoses get ya'...

They are independent of each other, but either one will contribute to overheating. Some people have looped the connection after having a problem with the heater hose or heater core. Burping is necessary any time you replace the coolant or any hose.

How do I make sure that theres sufficient coolant in both systems then? I added a gallon more in addation the the quart from last night, amd it seems to be maintaining much beyter temps. Ive been running it without load and the needle is sitting center and doesnt appear to be rising.

To burp your cooling system, run it for a while with the radiator cap off. Elevate the nose of the car slightly, just a few degrees will work. I suggest doing this outside, weather permitting. As the car comes up to temperature, the thermostat will open, and the coolant will circulate. Any air trapped in the system will get to the radiator. Since the radiator is the highest point, the air should exit, but it is also likely to push some coolant out with it. It also helps to tap the radiator with a rubber mallet during the process to break loose any bubbles trapped in the radiator.

I know that bit, and it seems to be doing fine now. I tested it under load and it actually ran cooler, from the cold winter air moving, I presume. Let me rephrase my question. The break was on the heater core hose, and that's where all the coolant was lost. Is refilling the radiator and burping the system the appropriate way to replenish coolant for the entire cooling system - or since they're independent and the break was to the core is there a step I have to take to make sure that portion of the system is good as well?

Perhaps I'm over-thinking it, the car is running at normal temps so far.

On a side note.. are there any advantages to the original braided hosing? When I get the chance to replace it, should I get another braided one or, are modern rubber makes a better choice?

Make sure the heater is on when burping. Air can get trapped in the heater core.

Thank you, that's what I was looking for. Fortunately, being below freezing I keep my heater on always. So I think it should be good. Thanks for the help.

Just be sure to check all of your coolant hoses and all of the other soft lines, too. A coolant hose going out is a pain. A brake line going out is a REAL headache.