Windshield fogging up on T2000

[tyates007]

So I started the Kenworth for the first time this year this morning to do some things in preparation for an up coming trip. Truck fired right up which was good, idled for about 2 minutes building air and then shut down, bad. There was a code on dash said low coolant. I checked the tank and sure enough it was empty. Put a gallon of coolant in, hit the key and we are back in business. I cannot see anywhere on the ground there is a leak. After truck has built air I turn the heat on and it immediately fogs up the windshield. I am thinking the two are related. In my lgt when this happened it was a heater core. Does this sound like a heater core? If so, anyone ever diagnosed or changed one out? Any help would be appreciated.

[Nuke-E]

That definitely sounds like a heater core, or possibly a connection to it. You can probably smell antifreeze as well--you're leaking at the heater core, then blowing water/antifreeze vapor all over the cab.

[Phil D]

I'd agree with your diagnosis. That said, I haven't had to replace my heater core yet, so I can't help much.

 

What I do know, from when I had problems three years with a non-operational blend door, is that the climate control system is pretty much entirely in that big module on the firewall, so it's likely that you'll have to get into that to replace the heater core.

 

When I stopped at J. W. Morgan's to get some heat in the truck for the rest of that trip back to Texas, Scrap was able to send J. W. some information about accessing parts of the climate control module, but he didn't send it to me, so I can't help you get to it. If Scrap sees this thread, though, he can probably tell you what you need to know about getting to that heater core.

[Scrap]

I haven't done a T2 core in years but it seems like it wasn't all that memorable. I think it just slid right out its trap door and it all stayed engine-side?

[Ronbo]

Phil how did you fix your blend door. On my 2000 the heater core is accessible from the engine side. Looks like it just slides out.

[tyates007]

I haven't done a T2 core in years but it seems like it wasn't all that memorable. I think it just slid right out its trap door and it all stayed engine-side?

I am a big fan of none memorable repairs. Thank you everyone for the replies. I will keep y'all posted

[Phil D]

Phil how did you fix your blend door. On my 2000 the heater core is accessible from the engine side. Looks like it just slides out.

 

Ronbo, I ended up taking it to the local KW dealer to finally get it fixed after I got home. The stop at JW Morgan's was for a temporary, manual adjustment to "full on" heat, since I'd spent an entire day driving while the ambient temperatures dropped from the mid 40s into the low 30s, and with no heat whatsoever coming from the truck (it didn't occur to me at the time to stop and see if any heat could be obtained from the sleeper heater). JW was able to slide it out and get inside to manually move the blend door into full heat mode, making the next day's travel far more pleasant, but requiring the following day's travel into south Texas to be a "windows down" event.

[Ronbo]

Mine doesn't blow out the dash, only defrost or floor.

[Phil D]

Mine doesn't blow out the dash, only defrost or floor.

 

That is a different problem than I was having, Ronbo. Mine was the blend door -- the one that varies the amount of air that's come through the heater core and controls the temperature -- not the diverters that control the output. I could get air from the vents, the defroster, or across the floor. The problem was that for much of that day, it was coming out at thirty-some degrees.