wet insulation at firewall

[vortec]

i was pulling an amp wire through my dash, last weekend, and found that my insulation against the firewall is wet (pass side). it's not a/c condensation (hasn't worked since i bought the k5) i've had the top off for a few months, but i keep it in my garage when i'm not driving it, so it has not been rained in. only rocks, not mudding, lately. only thing that makes sense to me is leaking heater core. i've never seen a heater core that's easy to get to. how bad are these? i haven't used the heater in about 11 months (because this is texas). i'm not totally against the idea of draining and bypassing the heater core.

 

[Cowboy_80]

You might think differently this winter, but that's what flanel is for. I've never replaced one, but I do know that bypassing it takes about 5 minutes, a screw driver, and a knife.

 

[Hogback Fabrication]

Replacing the heater core on a K5 is pretty easy but if you don't need it anyway:

To bypass the heater you just have to buy a plastic adapter from an auto parts store (5/8" to 3/4" or something like that, I think it was even packaged as a heater core bypass adapter). Then loop the two hoses coming out of the water pump.

 

[BLIDVL]

Pretty simple to replace, the hardest part on mine was getting the lowest bolt on it out as it is a completely blind operation unless you remove the inner fender. To bypass get a flush tee pull both hoses off the heater core and stick the tee in between them.

 

[vortec]

my dad and i bypassed the heater core on his old taurus a few years ago, and i think he still has plenty of leftovers from the job at his house. might fit mine.

since replacement doesn't sound as bad as most vehicles, i may give it a shot. not big deal if it doesn't work out. 35 degrees is very bearable once your inside the truck and take the wind and rain out of the equation. plus, it's not my dd.

 

[Thunder]

Its not that hard. I have to do mine again. I replaced the orginal core in 1999. Now its leaking again.
Heres a tech article:http://www.coloradok5.com/heatercore.shtml

 

[sta500666]

Before you go pulling the heater out (which isn't that bad of a job) 2 hours tops... You need to make sure its antifreeze thats leaking out of the heater. Does that damp spot smell sweet? If so its the heater core. You can also let ur engine warm up and turn the heater on, you will know within 10 minutes if its leakin cuz it will start to steam up and get real wet down there... like she said hahahaha! Ok bad joke

 

[vortec]

i tried to smell it when i found it. smelled a little like coolant, but i couldn't tell for sure with all the stuff mixed in. dirt, old insulation, etc.

since i haven't run the heater in nearly a year, i haven't noticed any steam, and since i have all sorts of wiring ripped out at the moment, i can't really drive it around. no way i'm leaving it running in the garage long enough to reach operating temp . whenever i finish wiring this junk up, i'll take it for a spin with the heater on.

edit: good article. thanks. i missed it when i was looking through the tech section.