Need help with heater core

[frank1927]

I have an '85 CJ7 6cyl
On the way home from Starbucks I heard a 'kerchunk". When I pulled in the drive, anti-freeze began pouring out of a drain hose under the battery tray, & little down the firewall on the passenger side. So, I'm assuming I need a new heater core. I don't know anything about that part of the heating/cooling system.
Will some one supply me with step-by-step instructions & list of parts I may need?
Thanks in advance
-frank

[Matt'sXJ]

Well if it is the heater core, you could bypass it for now. Just run one heater hose from the thermostat housing to the water pump. That will work until you can replace the core. I haven't worked under the dash on a cj but I would bet the heater box comes out fairly easy. I'll let someone else chime in on that.

[frank1927]

Hey Matt, thanks for the tip. I bypassed the heater core, & at least now I can drive it.

[1984CJ]

The heater box ( all of the black plastic under the dash) comes out as a unit.
Mark and remove the operating cables.
Unplug the resistor pack(passenger side, brown and blue wires)
Remove heater hoses.
Remove 5 nuts from the engine side of the firewall. One is hidden buy the back of the valve cover, one may have a ground wire on it the others are near and under the battery tray.
Unhook the blower motor wire.
Finesse the heater box out from under the dash.
Disassemble and replace heater core and seals.
Lubricate the linkages.
Replacement is the reverse with much muttering and groaning.

[Tree_Frog]

Make sure it's not just the hose first.

[Don]

--major snip--


Replacement is the reverse with much muttering and groaning.



Yep this sounds about right for whenever you are working under the dash. :eek:

[frank1927]

Thanks guys. It's pretty stormy here on the east coast today. If there is a break in the weather I'll try to tackle the job

[frank1927]

Well, removal was a lot easier than expected. It only took about 30 minutes. Were it not for the instructions & locations of the nuts, I'm sure it would have taken a lot longer, ending up with me ripping it out with brute force. I found it necessary to remove the battery tray. And while I have that out I'll hit it with some Por-15. Now I'm waiting for the new heater core to arrive. I sure hope the unit slides back in just as easily.