Heatercore Replacment how-to
I did my heater core today using the "cut out a flap in the heater box"
technique from driversfound.com, and wow - that was easy!
I was really concerned about the coolant shooting me in the face since I
decided not to drain it (I just changed it a few months ago), so I had two
big ass clamps, one on each heater core hose, and I closed the heater
valve with the hot-cold slider lever on the hvac control panel. When I
pulled the hoses, about 3 or 4 tablespoons gushed out followed by slow
drips. I jammed some small handle screwdrivers into the ends of the hoses
to slow the dripping and went to work. I'm definately glad I had the
tupperware tub there to catch the drips, though!
Its important when you're cutting out the flap to make sure you cut it big
enough. You will see two small "grooves" or "dented lines" in the plastic
where the heater core is located. Make sure you cut the hole as big as
possible. I blew it and about 2 inches from the bottom of the rearmost
cut, I curved in a little and the core would not fit through the hole so I
had to make another chop to get it to come out and it looks kinda corny.
Sealing the hole back up, I didn't use a soldering iron as suggested since
this wrecks the soldering iron. Instead, I used this stuff I got from
Rat Shack (radio shack) called "Brush-On Future Glue". I know it sounds
gay, but this stuff is cool! It bonds in less than 15 seconds, and its
strong as hell. I used a tiny tiny droplet of it at each side of the flap
at the top and held it there for about 6 seconds and when I let go it was
solid. Chemically this stuff is similar to the rear view mirror mounting
plate glue but isn't a 2 part glue. There are lots of subtle warnings
on the bottle about it gluing "plastic, wood, metal, fingernails, eyelids,
skin", and its especially nasty because it bonds so quickly, and when it
bonds, it gets hot! Don't ever take a whiff of this stuff, though, its WAY
worse than any chemical I've ever smelled before. Acetone, Xylene, Brake
Cleaner and Sarin Gas .. these are all like birthday cake compared to this
stuff! It must have been created by the devil himself.
I didn't bother to use caulk or glue to seal around the edge of the flap,
and its actually kind of a nice thing. I drove around with the heat on
today and now it blows lightly on my legs too, not just on my toes where
it usually blows.
Anyway, the big tip was about that stupid cover that you have to pull off
to get to the core. There are 4 screws on this thing. Three of the four
are easy to get to, the fourth is something of a nightmare unless you're a
midget contortionist. When I finally got it out I decided to just leave it
out for next time's sake. After I loosened the spring clamps and slid them
back on the rubber hoses and was ready to pull the hoses off, that damned
cover was in the way so I attacked it first with a dremel tool and cutting
wheel then a japanese pull saw. I made a cut from the edge that touches
the heater box to one of the hose ovals and pulled that hose out, then I
cut from that oval to the other oval and removed the other hose. Now I had
the cover free and sitting in my hand. With the cover installed you
couldn't see any of the cuts I had made at all so I wasn't worried.
Anyway, I did the rest of the job and when I was ready to put the cover
back on, I paused and looked at it for a minute. Then I got an idea. I cut
from the second oval shaped hole back to the screw hole for that 4th screw
that was hard to get to, and essentially cut the cover into two pieces.
This is great, because now I don't have to bend the cover all weird to get
the two hoses back in to their ovals, and I can put the piece of the cover
I cut off back on first, tighten the hard to reach screw easily, and then
put the rest of the cover on and the other three screws. Brilliant, I tell
Naturally, I didn't find any telltale pool of coolant in my heater box, so
I'm not sure if it was even leaking, but if I smell coolant this autumn
when I have the heater on, I'll know its something else.
The big flap cut in the side of the heater box doesn't look bad at all,
its hardly noticable. As a special treat, I peeled off all the half rubbed
off stickers covering the side of the heater box and now it looks better
than before down there!
Forgive me, I'm just carousing mindlessly...