Leaking coolant - help!!!

[jd21476]

I drove home the other day and smelled what I thought was coolant. I parked my truck and came out about a half hour later to find a puddle under the passenger side by the firewall. I immediately thought I must have lost my heater core.

I finally got around to pulling it out today (about a week later) and it still looks good. I ran some air through it and could not find a leak and then filled it with water and could not find a leak.

I got under the truck and could not find any leaks in the lines or anything. What else could it be?

**** Also, I have not been getting any heat from the truck lately so that also made me think the heater core was bad.

[old Rusty C10]

check for a pinhole in the hoses.. especially where they connect

[tucsonjwt]

Any green oxidation on the copper nipples of the heater core or elsewhere on the core? I would check right after parking after a long drive and check closely with a flashlight and inspection mirror. Something leaking that much should be noticeable at its source.

[donut]

May still be bad. Lost mine on Friday. Current only leaks under pressure.

Mine leaks when I shut the truck off after driving, when the pressure would be highest. I also get the "foggy window" thing. Currently only leaks when I shut the truck off. Obviously I also can't use the heat and am stuck with driving with the wing window open, luckily it's not my daily.

I may get lucky that it's only a hose, but not holding out hope as the HC is 25 yrs old.

[Corts60]

Sometimes a solder joint in the heater core will only leak when it is hot due to expansion. Replace it, you're there anyways.

[jd21476]

Yeah, I think I will just replace it. Its only $25.

[Bigstevex4]

Replace it any way got it out 25 bucks and your heat will improve.