Leaking coolant onto carpet and on ground underneath the car

[CloudNine]

Hey,

I am experiencing leaking coolant, some into the car onto the carpet below the dash, but most appears to drip onto the floor. If I park the car while running and then move it, there are two-three ounces coolant on the ground.
My mechanic tells me coolant is leaking from the condenser drain, and I need a new heater core.

My questions are:

How likely is this diagnosis to be correct? The car has been sitting a long time, in Arizona so there isn't a lot of corrosion. Could it be something else? Like a regulator?

If the dash is taken apart, are there other things that could be replaced while in there, that are troublesome? I know to replace bulbs.

If the dash is taken apart, is there anything in particular to watch out for? I have already pulled the dash pad, the glove box, the center console and the instrument panel bezel, none of which was too difficult.

Any other thoughts or advice?

Thanks.

[bluemax]

Yes, from your description, your heater core is leaking.

The good news is that you can replace it yourself, the bad news is it will probably take you 6 hours to do it (with an AC equiped car, heater delete or CP cars about 15 minutes). You are basically pulling the dash back far enough from the fire wall to access the HVAC/heater box.

I would put a flow restrictor in the line when you put it back together to reduce some of the pressure on the core.

[svono50]

I will second the leaking heater core...bummer, but not completely impossible. Nothing else you should do while in there, since your car is an AZ car, you should be good.

Personally I found it easiest to pull the front seats and drop the steering column. Yes, it takes longer, but it will allow the dash to lay outward enough to give you some nice room to work on the HVAC box and allow you to kneel in the position of the passenger seat. After doing ~6 of these on various Foxes over the years, it is my preferred method, YMMV. You don't have to blow your A/C charge if you take your time and get a little crafty. You can unbolt the heater box from the firewall and manipulate it inward/downward just enough to prop open the lid to get the old core out and the new one in. I used some deep sockets and short extensions to hold open the 'bear trap' lid during extraction/insertion. One thing to be very careful of with the new core is to not torque/twist/push on the inlet/outlet nipples during insertion of the core into the box or getting the hoses back onto the nipples. The main failure point on new cores is the solder joint between the nipple tube and core housing. There have been some folks that even resolder the tubes along with adding a brace between the two nipple tubes to help strengthen things up a bit. Do some searching, you should find some pics.

Take your time, breath on occasion and all should go well.

[spt87a]

I would put a flow restrictor in the line when you put it back together to reduce some of the pressure on the core.

Would like to see some other's experience with the flow restrictor on an SVO. The flow restrictor was recommended on 5.0L fox bodies by Ford but my understanding was as a fix for a gurgling sound from coolant flow that some owners complained of, not to address heater core life span. But it became common practice as a preventative measure for heater core failures. Is this really a valid use or urban legend though? The pressure in the system is still the same as set by the radiator cap rating so I'm not sure less flow really reduces stress on the core significantly.

I don't think Ford ever recommended flow restrictors on 2.3L cars. On the SVO, when I look at the coolant flow diagram the heater core is inline with the oil cooler. Reducing the flow in this circuit seems like a real bad idea since now the oil cooler also gets less flow so the oil cooling capacity is reduced.

On my SVO I put a flow restrictor in at the same time I needed to replace the thermostat since I had it drained down anyway. After examining the cooling flow and realizing the oil cooler was affected I later removed the restrictor. On my 5.0 GT I did put in a flow restrictor but the core started leaking anyway (the core may have already been on the way out though, long story short when I bought the car it was bypassed, I reconnected it using a restrictor). On the 5.0 I do plan to keep the restrictor since I don't see that it causes harm even if it may not really help anything.

One last thought - blasting the heater is a trick I've used to avoid overheating at times. In the SVO when the thermostat was bad this saved the day for example. I've done it with other vehicles too - a Ranger with a bad fan clutch for one. Without the trick I would have been broken down in rush hour traffic on a major highway! The flow restrictor will reduce the effectiveness of this since with less water flow you get less heat transfer. Certainly not a common thing but could save from being towed in a pinch. On second thought maybe I will remove it from the GT.....

[svono50]

My opinion is that the flow restrictor only reduces flow and not pressure...not in a hydraulic system like our cooling circuit and falls more into the urban legend side of things. I know some folks argue that it prevents excess pressure into the heater core, but this isn't an air circuit, it is only reducing velocity and not pressure so I don't see a need for it IMHO. As you noted, the oil cooler is inline with the heater core, so you also end up limiting flow through the cooler as well, which is something you shouldn't do as well. Just my $0.02.

[SVOeric]

to add to Ted's post--
flow isn't what kills heater-cores. pressure is (plus weak welds on the core, + years of service)

The only thing I've seen done that I think may help is reinforcing the joints on the core before install.

[spt87a]

The only thing I've seen done that I think may help is reinforcing the joints on the core before install.

Are you talking about resoldering some of the joints to make them stronger? Where the tubes for the heater hoses connect to core?

[svono50]

Are you talking about resoldering some of the joints to make them stronger? Where the tubes for the heater hoses connect to core?

Correct, that is the main point of failure from 90% of the failed cores I have seen. Another 'trick' is soldering on a bridge strap across the two tubes to tie them together to reduce the chance of breaking the tube-to-body solder joints. Most straps I have seen are hooked ~1/4 way around the tube to get as much surface contact/strength out of the strap.

When I was doing some intake gasket repair on my wife's former 86 5.0L, I was removing the heater core lines for better access and during breaking the hose loose, the nipple pipe went 'tick' and then rotated...DOH!!!! Made that job just a bit larger than originally anticipated. It turned out to be a blessing in disguise, as the shop that had previously replaced the heater core (before I met my wife) didn't install all the dash mounting fasteners, which explained why her dash bounced around so much. I replaced all the missing fasteners (~6-8 of them!) and it was very noticeable how much quieter the dash was along with much less movement...only so much you could do with a Fox convertible body. Not sure if a reinforcement strap would have helped me out, but I have a feeling it could have.

[gbeaird]

to add to Ted's post--
flow isn't what kills heater-cores. pressure is (plus weak welds on the core, + years of service)

The only thing I've seen done that I think may help is reinforcing the joints on the core before install.

Haven't some actually soldered support brackets from the core to one, or the other, outlet tubes on the newer cores? That fix is to prevent the tubes from cracking or breaking off when the hoses are installed/removed? Or am I confusing that with another vehicle in our hoard?

[svono50]

I thought I remember seeing them with the brace tying the two tubes together, but now that you mention it, it could have been back to the core endcap. Looking at the core tubes, you have options. One writeup I noticed out there the guy goobered JB Weld over the solder joints to reinforce the joints...just not sure how well the bond would be and just how much strength that would add vs a brace/bracket.

[CloudNine]

Update. Heater core replaced and back to working fine. Next question....in dash center behind floor console is an '80s looking electronic box wired into the car. It is an "Audiovox" that appears to be an aftermarket alarm? Although I have no fob for it. It has a switch labeled "siren" and a button. There isn't any horn under the hood. It appears to be aftermarket, except that also wired into the box is the wire with an inline fuse that connects to the floor console. This specific wire appears in the Ford service manual I have, so that appears to be stock? Any insight what we have here?

[GAboySVO]

I have never seen anything like that under my 86 dash. My guess is aftermarket and can be removed.

[CloudNine]

I have never seen anything like that under my 86 dash. My guess is aftermarket and can be removed.

Thank you, that is my thought as well. I don't think Ford ever put any aftermarket brand electronics in the car at the factory.

My A/C unit is dealer installed. Back in the '80s many features such as Cruise Control, radio, A/C were added by the dealer.

Maybe this was another dealer add.

[CloudNine]

IMG_0674.jpgHere's a photo of the 35 year old heater core. The tubes appear to be solid. Staining is seen in one spot in the upper left, and across the core near the right.
There was quite a steady leak, glad to have it repaired.

[svono50]

That core is certainly shot and in one of the core tubes vs an endcap or inlet/outlet tube, good thing you got to it sooner than later for sure.

Are you saying your SVO's A/C unit was dealer installed? If so, it would make me wonder if your car was a Comp Prep that was basically reversed, as A/C was standard on our cars and removed for the 'option delete' and Comp Prep cars from what I know. Interesting.

The Audiovox was possibly a dealer up-sell or the owner had it added soon after purchase. My 86 had a still semi-functional Chapman alarm on it when I bought it. Luckily the lock cylinder was under the steering column vs in the front fender like they typically were. When you pressed in the lock cylinder it activated a slide hood latch and as I found out while driving along...an ignition kill!! Since the Chapman key was on my ignition key ring, I had to coast to a stop with my flashers on to pull the keys and unlock the Chapman to restart the car. Very quick learning experience and I removed that system the next weekend.