I'm thinking the heater core in my '98 D1 just pooped the proverbial bed...
Passenger side carpet is wet, resevior was empty, steam was coming from the glovebox, and after the old "heater bypass" trick, everything appears to be back to normal. (Minus working heat, of course.) And, for extra fun, this all happened while my significant other was driving back from the store with her son.

Haven't had a chance to do some RAVE research yet; is there anything else that would cause this? Is there a hose or valve under the dash that might have gone bad instead? I remember reading something about these trucks "being built around the heater core."

Thanks all!

 

You can replace the heater core without removing the whole dash.
There is not much else back there that could have done this, have you ran your finger through it to see if it feels slippery?
How does it smell? Taste sweet or really bitter?
Then its def engine coolant.

 

I'm sure it was coolant. Once the carpet dries out I'll crawl under the dash and try to see if I can tell where exactly it was coming from.

 

If doing a heater bypass be sure to make the connection with some hose, as opposed to just stubbing off two ends. You want that water flow.

 

The hose I had wouldn't bend without kinking, so I McGuyvered a quick turnaround with some 1/2" copper plumbing fittings I had laying around.
Guess it's back to the pull-a-part to practice taking out a heater core!

 

Best tuition for $2 .....

 

Hey OP yeah its your heatercore. I did the same thing at the junk yard, good experience to get familiar with the parts.

You can remove the whole dash but there is a short cut method. Spike knows about the D1 more than I for sure but on a DII, you'll notice a screw that is reversed(meaning the head is facing the firewall), holding the heater pipes in place. You can loosen it with a pair of pliers. Then you need to remove the bracket holding the pipes to the core.

Once that's done there are about 4-5 bolts holding the right side of the dash. You'll need to remove blower motor as well. Then you can carefully bend the right side of the dash back and flex it just enough to slide the heater core out. Be sure to read up on the RAVE manual. This short cut is not something I've personally tried, but I read about it on another forum. I removed the entire dash basically for experience purposes and I wanted to make sure I was doing it by the book. The little brass screws seemed to strip fairly easily so be mindful of that.

Good luck

 

Thanks for the advice!

 

Got a replacement core & hoses from the boneyard. Turns out the return hose (top) was leaking, but I'm not sure if that was my fault for manhandling it too much to get the old core out & kinking it up a bit.
Major PITA, took all day and I didn't even pull the entire dashboard out! Just moved the passenger side, as suggested. But it's fixed. Cleaned the leaves out of the blower motor while I was at it.

 

Can you give us a better idea of what you did to fix it?
Like a small walk though or some thing to help others?