GEOz2k7

what does it take to install a new heater core in a 84 4runner. mine is leakin right at my fire wall at the hardpipe on my heater core. sometimes it leaks bad sometimes not at all. any input? can i bypass it? i know theres a rear heater to. id like to keep my heater but idk if its worth it to me to rip it all apart.

rokblok

iTrader: (1)

I would check to make sure that it was defintitely the core. Usually, in my experience, once the copper cracks, splits or anything like that, it is a pretty consistent leak. And it usually not a lot. More like a seep or even a drip. Hoses or if the hose doesnt seal to the core well, will cause a good leak. Just my experience. And its easier to replace a hose or a clamp than the core. In most cases...

GEOz2k7

how do i bypass my heater core?

TinMan

Replacing your heater core is a pretty involved process. Basically the whole dash and everything under it has to come out. Once you get that far replacing the heater core is really simple. I would say to remove everything that covers the heater core, get the old one out, install the new one, clean all the duct work, replace the worn out duct seals, and instal everything would probably be a solid 10-12 hour day. That's if your are a decent wrench. If not plan for a long weekend.

If the inlet/outlet pipes are cracked or otherwise bad, you are still looking at the same work to get to them, and at that point you might as well replace the heater core just so you don't have to go back in there for awhile.

GEOz2k7

ok well thats rly ˟˟˟˟ty, how do i bypass it with a rear heateR?

TinMan

Do you bypass the front, but still have the rear working? Get a piece of 5/8" heater core hose, run it from the outlet side of the heater valve on the firewall down to the coolant pipe that is behind the head. I'll try to post pictures of the tonight. Kind of hard to explain.

GEOz2k7

if u can post pics ill be greatly appreciated thanks!

4Crawler

iTrader: (3)

Heater valve on the firewall:
http://www.4crawler.com/4x4/CheapTri...ne_Pix/14.html


Front heater hoses are the two that go through the firewall. Just loop them together, disconnect the hoses that pass through the firewall and hook up enough hose to the two exposed fittings and that should do it. I did the same with my rear heater, bypasses it and the front heater still worked fine.

GEOz2k7

The one in red connect it to where?? The instructions weren't to clear sry. the hose to left of red one is leakin connecting to firewall. what hoses exactly do I connect? Can u color code it? Thanks crawler helpin me a lott

4Crawler

iTrader: (3)

Neither the red or green one, those are for the REAR heater. That is what the text on the page is talking about.

So the OTHER hose out of the valve is the one you want. The valve is fed from the engine coolant tube, then flows through the valve, to the inlet hose that hooks between the valve and the heater core (passing through the firewall). Then the return line comes back from the heater core, through the firewall and back to the engine coolant pipe. So basically you have the two rear heater hoses that go down under the body to the rear and you have the two front heater hoses that go through the firewall. So call those two hoses A and B. Disconnect A, disconnect B, take a piece of long enough to connect between where A and B used to be connected.

4Crawler

iTrader: (3)

Neither the red or green one, those are for the REAR heater. That is what the text on the page is talking about.

So the OTHER hose out of the valve is the one you want. You can see the hose that comes off the valve to the left, then it bends down and then back to pass through the rubber grommet in the firewall. The valve is fed from the engine coolant tube, then flows through the valve, to the inlet hose that hooks between the valve and the heater core (passing through the firewall). Then the return line comes back from the heater core, through the firewall and back to the engine coolant pipe. I think the return line connects to a tee where the green circle is, so that is where the rear heater return and front heater return lines joint with the tube running back to the engine.

So basically you have the two rear heater hoses that go down under the body to the rear and you have the two front heater hoses that go through the firewall. So call those two hoses A and B. Disconnect A, disconnect B, take a piece of long enough to connect between where A and B used to be connected.

4Crawler

iTrader: (3)

These pics. were off my '85 4Runner, assuming the '84 is laid out similar, if not just find the two hoses go through the rubber grommets in the firewall and those are the two lines to the heater core.

Here is a slight different angle. Red line shows hot inlet flow from the valve, blue line shows cool return flow from the heater core:



Different angle again, red=inlet, blue=return, and purple line shows where to bypass the heater core. Disconnect red line from valve, disconnect blue line from the tee fitting down low and hook up the purple line from where the red line was disconnected to where the blue line was disconnected:

GEOz2k7

thank u man! definate props, u should get this stickied since it is a good write up and not a lot of people wanna replace there leaky core lol. thanks a lot 4crawler! u da man!

GEOz2k7

should i cap off the part goin into firewall?

mike dominguez

where do I find brass fittings that connects to the heater core

mike dominguez

where can I find brass fittings that connects to heater core

mike dominguez

on my 1985 Toyota 4 runner

thefishguy77

iTrader: (1)

Deleted. My bad