Coolant leak - heater core

geopig

New member
Hi all

So I was driving home Sunday afternoon when I got a hole in the hose that goes from the heater core to the intake manifold. Got her home with some hose repair tape and a couple of extra coolant stops.

So this afternoon I replaced both hoses that go from the heater core (one to intake, one to water pump). So I start her back up and I'm now leaking from the heater core area. I believe the leak is coming from the copper pipes that stick through the firewall. It was tough getting the new hose on and I think I may have busted a pipe.

So my question is (having not removed the heater core yet) is whether I have to replace the whole thing or can I just replace the pipes that stick through the firewall? Thanks in advance for the advice/help.
 

If it's just the inlet tube you can splice in a piece if your very good with a torch.
But I would take a very good look at the core itself after you remove it for more damage. Getting broken by a little rough handling putting on a hose would indacate that your core is ready to be replaced....

Captain we have a core breach!
 
Sounds like you will have to replace the whole thing,, the pipes are not real long and probaly have worked loose from where they connect to the coils
 
Yeah, just went over and picked one up. Hope it is not to tough to install. Sounds from other threads that it shouldn't be too bad.
 

Rebuilding a 2.5L

untill cold weather just loop the heater hose back to each other and the leak will stop. then you can remove the heater core and clean the heater box and ect.. takeing your time and doing a real good job. Do the blower up grade ect... while you are at it. tug
 
I replaced mine about a week ago and it was a cinch.

Here is what you have to do:
1. drain about 2 qts of coolant from your radiator (might be a good time to flush the entire system)
2. disconnect the negative terminal from the battery
3. disconnect the two heater hoses (make sure you don’t drizzle some coolant onto the starter – your jeep will have trouble starting up and it’ll take about two days to dry out)
4. remove 4 nuts from the firewall (on the engine side) that hold the heating unit under the dash.
5. go under the dash and carefully pull the entire heating unit. Make sure you disconnect the three (3) cables that connect to the vent flap, heater level control, and defroster. Don’t forget about the accordion air conduit that connects to the defroster. If you have an AC unit, you’ll have to loosen that (but not disconnect the hoses) to gain more access space for pulling the heating unit out.
6. Once you have the entire heating unit out of the Jeep, remove the backing plate (there are about 10 or so screws that hold it) and replace the heater core unit. Before putting the backing plate back on, you might want to lay some silicone around the perimeter.
7. Just reverse the removal steps and you’re in business.
 
Nice call Tug, depending on how my time looks I may just do that! Don't think I need the blower upgrade, mine works like a champ! My last YJ definitely needed the upgrade but this '91 works great.
 
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