The Stovebolt Site Forums The Shop Area Interiors Leaking coolant at heater

On my 1947 coolant has started to leak at the bottom of heater where the hose from water pump connects. I hope the hose is bad and not the actual heater leaking. I did not turn the heater on. Also the cut off valve on the top hose in the engine bay is frozen and will need replacing. Do I need to lower the coolant in the radiator to prevent leakage when I replace the hoses and where can I get a new cut off valve? Thanks, ray durham

You can find a cut off valve on eBay. You can either find one controlled by a cable or you can get a 100% manual one which requires you to open the hood and screw it clockwise to cut off or counterclockwise to open. I think I'd get a bucket and drain the coolant out of the radiator & block to prevent leakage. Good luck. Heaters this old are notorious for getting thin, cracking and leaking. The good news is you can make one out of 1/4" copper tubing wound into a spiral and a couple of 1/2 to 1/4 copper adapters (assuming yours is a circular coil). If you need information on how I did that, just let me know.

If you're just trying to stop the leak, you'd either need two cutoff valves, or just loop the hose back to the connections at the water pump and block.

yes you need to lower the level of coolant to remove and inspect the hose.

I would inspect with a mirror and flashlight and see if you can determine the problem before you disassemble anything. If it looks like it is leaking at the junction of hose and heater, just tighten the clamp and observe. Most often this is the issue as the hose shrinks over time. If is looks like it is the hose itself or within the heater, then you need to lower the coolant and remove/fix the offending part.
Kent

if the hose has shrunk it needs to be replaced. tightening won`t help that kind of deterioration.
its just a section of heater hose.

Wonder why the water pump hose is 5/8 and the engine hose is 3/4. I have ordered 2 shut-off valves. One is used at firewall near heater and the other screws directly into water pump. I will probably go with the one at the water pump. Also will use new hoses. Curious...do you believe black pepper or a store bought stop leak product ever actually work? I noticed a little wet spot on my radiator in front of the fan. Thanks, ray

It has been like that since the days of the dinosaur.

Ray - Just my personal opinion, but I avoid anything remotely like stop leak stuff like the plague! It seems to cause bigger problems down the road. If the radiator is showing signs of leakage, that may be just one of many possible spots. The weakest link theory and all that. I would suggest getting it checked and repaired by a radiator shop if you have one. Others will likely chime in with their suggestions and personal experiences.

Ray, I'm 100% with Dan. There once upon a time was a product that would stop radiator and heater core leaks pretty well...unless you had a system that required more pressure than about 9 or 10 pounds. In that case you had to leave your radiator cap un-sealed or it wouldn't work. It thankfully is gone now because as Dan said it would stop leaks and then later it would cause many more problems...some of which meant you would get the chance to have your radiator's core replaced because once it set it was in there until the cows came home. As for black pepper, theoretically it can work but anytime I've seen this done it was (a) a waste of black pepper (and only the Easter Bunny and the Tooth Fairy know how much to put in), (b) temporary...actually very temporary and (c) only worked on really tiny leaks---if it worked at all. The whole idea is it swells up when it gets wet and if it manages to find the pinhole leak as it is swelling up, it might stop it. Until you build up any pressure, that is.

However, you can use black pepper to stop bleeding. At least according to the Tooth Fairy and the Easter Bunny. And again nobody knows how much to use. Probably best to apply to steak, pork chops, hamburgers, etc.