I have discovered a coolant leak behind my left rear tire. Irritating, as I just replaced the front heater core a few thousand miles ago... Vehicle has 175K miles on it, is a 5.4, and lives in Atlanta where we have yet to see freezing temps this year. What is the likely cause of this, and how bad of a repair job is it? I found nothing about it in my haynes manual. Thanks in advance for you help!

 

It's from either the heater core or coolant lines for your rear heat. The lines are metal but can be replaced or spliced with rubber hoses according to other posts i've seen on the subject. If you don't want to fix it you can cut the lines at any point and loop them back with a hose to stop the leak. There may be a good spot to loop the lines back near where they leave the engine but I'm not sure.

 

My friggin heater line rotted at EVERY hold down at the body, it was leaking in that same location, removing the hold downs before and after the leaking area revealed future leaks, basically the bracket was holding the fluid in those areas. Rather than replacing the entire line, I just replaced the bad portion with rubber hose, hoping to go back with either stainless steel or copper line later. Smart company to not use stainless steel for a heater line that is 10 feet long coming and going to the rear heater core, dirt and water collect at the hold downs and eat through the lines.

 

Bummer. Where do the lines tap into the system up front? I'm tempted to bypass it. I use rear air quite a bit, but I've never needed rear heat. The van's main job is towing a racecar and that primarily happens during warm months.

 

Lift the doghouse, you'll see 2 rubber lines going to steel lines, shotty dealer simply folded one of my rubber lines down, pinching it off, stopping the leak and making the heater inefficient. I was in the doghouse replacing the AIC and noticed the hose down, thought it was an accident, weeks later I figured it out. I'd show you a pic, but this site refuses to allow links to where I have it, so I can't share it here, way to go FTE.

 

Thanks for the help!

 

no problem, you could find many like I did, the hold down clamps are poly and wrap around the lines, causing it to rot, plug it at the dog house.