Coolant leak on passenger side floor

-
1970Dart198

1970Dart198

Well-Known Member
Joined
Jun 11, 2013
Messages
170
Reaction score
10
Location
Greenwich
I have a 1970 Dodge Dart Swinger with a 198 slant six.

About a year ago, I noticed a small coolant leak onto my passenger side floor, with the drips located below a big black box under my dash (heater core?)

Just recently, the leak has gotten to more than a few drips, but not significant enough to actually lose any major coolant. My heater motor works, and gets very warm very fast.

I notice that if I leave my car for extended periods -about a week or so- there is a noticeable amount of coolant on the passenger side floor.

How easy is it to replace the heater core in my Dodge Dart?

I do not have A/C in my car.

Thanks.
 
Although I couldn't tell you exactly how to go about doing it on your specific year, I can tell you they are not expensive or hard to replace.
I copied and pasted this from an old FABO post.


Step 1: Drain coolant. Step 2: remove heater hoses. Step 3: remove bolts from around the heater blower motor.(Under the hood) Step 4: look beside the passenger kickpanel and straight up for the nut on the support rod that goes up inside the cowl vent and remove it. (this rod is a lot like a battery hold down rod with a hook on top that simply hooks into the vent to hold the heater box up). Step 5: wiggle the heater box backward (towards the seats and down until it drops to the floor. Be careful here as there is coolant in that old heater core that can ruin your carpet's day. Step 6: Remove control cables and unplug the resistor and disconnect the defroster hoses. Step 7: Take heater box out of the car and lay it on the ground. Step 8: Disassemble the heater box.
It is held together with spring clips and once they're removed the two halves separate quite easily. The heater core is held into the housing with a few screws. Now you're home free.

This is pretty close to the same as with my 73, but both have small glitches to deal with (like the hose tubes not being in exactly the right place but close enough. :)

I cleaned and painted mine before it went back in, and while it's out and apart is a really good time to replace any foam seals for the doors that change the airflow.
That 1/4 grey foam weather strip that is sticky on one side works great for that.
 

Attachments

  • heater ready.jpg
    25 KB · Views: 347
Thanks! I'm not at home, I'm in college right now, I have a pan to collect coolant, but I would prefer to do it at home. Can I do it in a parking lot?

What are some signs that the leak could be getting worse? I don't want to be driving home 3 weeks from now and have the coolant burst in the cabin while on the highway. Do you think I'll be good for now until I can get better facilities to do the job?

Thanks!
 
1970Dart198 said:
Thanks! I'm not at home, I'm in college right now, I have a pan to collect coolant, but I would prefer to do it at home. Can I do it in a parking lot?

What are some signs that the leak could be getting worse? I don't want to be driving home 3 weeks from now and have the coolant burst in the cabin while on the highway. Do you think I'll be good for now until I can get better facilities to do the job?

Thanks!
Click to expand...

Most of the work would be inside the car, so a parking lot wouldn't be bad I don't think.
You might want to opt for bypassing the heater until you get it where you want it.
Just loop one of the heater hoses back to the water pump where the other hose connected.
 
Sounds like a pretty good project! I'm going to wait until i'm back home a few weeks from now, as its not bad at all, just a few drips of coolant.

I'm going to get the heater core pressure tested and boiled out at a local radiator shop I know on the CT/NY border. I know the replacement heater cores don't exactly fit the best, and I would like to use the same heater core if a small leak's all it is.

I would like to use my heater for my drive up to CT from South Carolina, quite a temp change from South to North!

Thank you!
 
No problem.
If it blows on the drive you can stll bypass it, but it'll dump your coolant in the floor.
It could really be an issue if it leaks enough to steam up windows in cold weather.

You could make it without a problem too. :)
 
The two hoses are a different diameter. I had to bypass mine for a short bit so I bought brass fittings at Lowes. It gave the best seal. This is a very worthwhile project as you will also be able to clean out 40 years of leaves, dead bugs and pine needles.

View attachment DSC_0049abod.jpg

You can buy kits online with all the foam and seals if your like.

The new heater core I bought didn't fit. The tubes weren't soldered on exactly correct and they need to be. I tried three different ones. I brought one to the radiator shop and they resoldered the tubes where they needed to be. He told me that he could have just made me one too.

While you have the heater box out, clean out the cowl as best as you can from the opening under the dash.
 
That's what I was reading about! They dont make new heater cores that match correctly in size, so I'm going to get mine cleaned and boiled out.

Like you said, it'll give me a chance to clean out all the stuff in the heater box, and build it back like-new.

My heater works fine right now and gets real nice once warmed up. It seems like a really easy job to do, and I look forward to doing it.

I've talked to other people who have found pretty interesting, and nasty things in the cowling and heater boxes of their cars.

BTW I like your picture, it looks kinda like my car, probably running better than mine, but hey! Its a fun project especially if its a daily driver!
 
What you can do for the time being is buy two manual heater valves, one 1/2"and one 5/8". Install them in the heater hoses. If it was to rupture on the way home you can shut the valves off and keep on trucking.
 
The larger of the two hose clamps is capable of pinching down a fresh cut of the end of the 5/8 hose to the half inch nipple if needed.
Been there and done that. :)

On the new heater core I just heated the solder joint with a wet towel around the other area's and moved the tube where it needed to be.
It was only off by a little bit, but the core itself fit perfect.
 
The heater cores are fairly inexpensive (~$40), so order one now (rockauto for me). If it isn't fogging the windshield on a cold night, you should be OK for a few months. They don't normally blow, just drip and rust out the floor under the carpet. Just have a hose loop ready or block-off plugs. If stuck on the road without, you can just loop one hose back to the other port.
 
I ordered the heater core and its being shipped to my house in Connecticut! It seems like a fairly easy project. I have a pan underneath the heater core to collect the few drips that come out of it. I drive the car every weekend, but it sits all week! Military college doesn't give me many chances to leave during the week!
 
1970Dart198 said:
That's what I was reading about! They dont make new heater cores that match correctly in size, so I'm going to get mine cleaned and boiled out.

Like you said, it'll give me a chance to clean out all the stuff in the heater box, and build it back like-new.

My heater works fine right now and gets real nice once warmed up. It seems like a really easy job to do, and I look forward to doing it.

I've talked to other people who have found pretty interesting, and nasty things in the cowling and heater boxes of their cars.

BTW I like your picture, it looks kinda like my car, probably running better than mine, but hey! Its a fun project especially if its a daily driver!
Click to expand...

I just bought one at NAPA a couple of months ago that was a perfect match. Fit like a glove.
 
Also,the carpet will stay damp since antifreeze doesn't evaporate and will rust out your floor.
 
Pretty sure that the heater core is the first thing coming down the production line, and then they build the rest of the car around it. ;)
 
So I finished the job a few hours ago! Not all that bad. Removing the glovebox is a must to get at all the connections easily. After that it was pretty straightforward. There were a TON of leaves and other decaying matter in there. I cleaned it up well and restored gaskets and the foam cowl seal. Now the new copper heater core, that is a long story with many used Dremel cutting wheels. The new core fit, but not snug like the old one. So I cut it to fit! After installing and filling with coolant, the Dart heats up really nice!

I wasn't a fan of the aluminum heater core spectra premium sent me so I got a copper one from advanced auto. Thoughts on comparing copper and aluminum?

Thanks!
 
My 06 Town and country front heater core literally split at about 6 seams, all in a matter of 5 minutes. Very strange. Its even easier to pull than yours though. The new one was brass, the OEM was AL. It never overheated though, but got pretty low coolant wise. I changed the rear one before it let go as it was the same age. Coolant is slippery too, and a bear to get out of carpet.
 
1970Dart198 said:
Thoughts on comparing copper and aluminum?

Thanks!
Click to expand...

You get more money for copper at the metal recyclers. :)
That's about the only reason it matters, as they both work just fine.

Due to electrolysis the copper might last longer though, but I don't know for sure.
 
1970Dart198 said:
... Thoughts on comparing copper and aluminum?
Click to expand...
Interesting that there is an aluminum heater core for your car. The ones I bought on rockauto for my early A's are copper.

Aluminum transfers heat a little better, I think more from the manufacturing process than the metal itself. However, probably only an advantage to those in the far north. Copper usually lasts longer, but costs more and is heavier. Aluminum can be destroyed in a week from electrolysis (from bad grounds). I don't particularly like the newer heater cores, w/ crimped-on plastic tanks w/ rubber gasket. However, the ones in my 1996 & 2002 minivans are still fine after many years, plus those are cheap and easy to change (pull out a side door of heater box). My 84 & 85 M-B have monster heater cores (for German winters), that cost $400 and take 2 days to change (remove entire dash). They have the crimped-on plastic tanks and the gaskets shrink and leak over time. I prefer "crappy U.S. design" to "exquisite German engineering". I am slowly converting all my cars to Evans Waterless Coolant to eliminate corrosion problems.
 
You must log in or register to reply here.
-

Back
Top