Hello everyone, I have a question about the replacement of the heating system in my 2001 XLT. My entire heating system is rotted out, both heater cores AND lines, and I plan on replacing it all before it gets any colder out. We're native southern Californians about to experience our first PA winter after all!

So my plan is this, replace both cores, route (carefully) new hose to bypass the rusted out lines to the rear core, replace all the junctions in the OEM setup under the hood with whatever "T" configuration etc. is needed, and finally, I was planning on just using hose clamps instead of the quick connectors.

I was reading that the 4Runner guys have luck with running rubber hose to the rear of their vehicles, and I feel I can make a good setup with careful routing and plenty of P clips. As far as the quick connectors though, how important are they really? I've read of people worried about leaks using hose clamps, but no claimed instances of leaks. And I have read of a couple of people using hose clamps without a problem. I'll get the connectors if I have to, but I just want to know if anyone else has not used them in favor of clamps.

 

Just curious how you have determined everything is rotted out? Have you inspected both heater cores and lines?

 

When I bought it the entire cooling system was rusted. It looked like the PO was running straight water. I went through the entire system to clean it out the best I could, and the only thing that happened when I tried to turn the heater on was cold air blowing and my new 50/50 mix looking like chocolate milk again. Only thing that wouldn't clean out was the heater lines. I hooked up a garden hose and could only get a trickle of chunky rust water. It was early summer then, so i just bypassed the heating system. I just want to replace as much of the rusty old system as possible and have heat!

 

Hey Ekliss,

I came across your post while searching - did you get this resolved?

In case you have not done this job yet, you might want to check the lines running to the back - on my 99 they are aluminum - I have had break lines and transmission lines rust out thanks to the winter salt but I am just now working on replacing a blown heater hose and inspected the lines running to the rear and they are fine. I believe the heater cores are also aluminum. So they may be OK if you flush them out.

Once you get the heater hoses off, you can rig up some clear hose from Home Depot or Lowes onto the front core and the lines running to the rear and flush them out with a garden hose - but be careful about the pressure - if you put full house water pressure on them you may blow something out.

Regarding replacing the factory heater hoses, IMHO getting the old hoses off is 90% of the battle - if your lines to the rear are in fact good, it would be much easier just to go back with the factory style hoses.

I would think your radiator would be more likely to be shot than the heater cores and lines. I have a 93 F-150 that had straight water in it and the rust sludge collected in the radiator and pretty much filled it up. Be sure to check that.

 

I did get it resolved. I just tore out the lines and ran heater hose to the back. Im not sure what caused it, but the lines were full of flaky corrosion. It was multiple layers of thick, chunky, flakey rust (so thick it was completely plugged in one of the line ends) when I tried scratching and scraping it out, it left behind pitted aluminium. I could only scrape so far, and I figured the rest of the lines were just as bad, so I ditched them. I wonder what caused it, and what the inside of my engine looks like!
Anyway new heater hose ran with "P" clips, a couple 5/8 tee's, and quick connectors worked out great. Its been a few months of driving in a warm and toasty expedition.

 

glad it worked and is in your rearview mirror.

I got all my hoses off and discovered the connector for the knock sensor has rotted and the wires have lost their insulation for about an inch where they go into the connector. Most likely they were just hanging in space and not touching cause it was not indicating any codes.

Of course there is ZERO space to get back in there to work on it so I am pulling the intake to get to it. Fun times!

I love Ford but sometimes I wonder why

 

Yeah this is my first Ford, although I've worked on a few. I have always heard (and I suppose bought into) the Fix Or Repair Daily stigma, but when I think about all the people that actually own them, they all seem like satisfied owners. My dad bought a then new 93 ranger, and aside from a cracked intake manifold and routine maintenance, it ran like a top for over 300k up to the day he got rid of it! I'm loving my Expedition, I just think routine maintenance is the key with any vehicle, but maybe especially Fords ;-)