Radiator stop leak

Messages
143
Location
ca
The heater core of my 04 2500 dodge ram 5.9l cummins is leaking out the catch pan tube in the firewall. I'm capable of pulling the dash and replacing the heater core, but I don't have time to do it. A very mechanical guy I know recommends radiator stop leak to seal it up, but I've heard horror stories about it clogging up engines and having overheat issues. Part of me doesnt want to touch the stuff and part of me thinks those horror stories are from people who thought "more is better" and probably dumped a whole bottle into the cooling system and plugged it up. It's not leaking really bad. Just leaving a small puddle under the truck. Anybody have anything good or bad to say about this stuff? Thanks
 
Messages
12,946
Location
ROCHESTER, NY
Yeah, the last time I used that stop leak was many, many years ago and it worked with limited success. But, it doesn't last forever and you will probably need to replace the heater core anyway. It sounds as though you'll be keeping the vehicle for some time so, you may be better off replacing the heater core. If you can live with it leaking til you can replace it properly, then this may be your best bet...IMO! EDIT: OR, if you don't necessarily need heat, bypass the heater core all together and put in an elbow(or whatever) between the two hoses(inlet/outlet) and run it that way temporarily.
 
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Messages
816
Location
Twin Cities MN USA
Our Buick was in a minor accident resulting in a small crack at a mounting tab on the tank. The Ranger was also leaking from the timing cover. I used ACDelco radiator stop leak, which I believe is vegetable based. Both vehicles have been leak free for 3 years. They both put out very good heat also.
 
Messages
1,038
Location
Minnesota
The best stuff out seems to be the GM recommended brown tablets that are about 3/4 inch in diameter. The are beet pulp that has been dried and pelletized. They seem to do a good job of slowing/stopping the leak without clogging anything up. My recollection is that they add a couple of these pellets at the factory as well. Three pellets stopped a leak from either the water pump or intake gasket on my '06 3900 engine a month ago.
 
Messages
1,472
Location
New England, USA
Originally Posted by Lapham3
The best stuff out seems to be the GM recommended brown tablets that are about 3/4 inch in diameter. The are beet pulp that has been dried and pelletized. They seem to do a good job of slowing/stopping the leak without clogging anything up. My recollection is that they add a couple of these pellets at the factory as well. Three pellets stopped a leak from either the water pump or intake gasket on my '06 3900 engine a month ago.
+1 The best answer is to address the leak, but short of that, the GM tabs are the only ones I would use.
 

monster1

Thread starter
Messages
143
Location
ca
Thanks for the replies. I've confirmed that the tank is aluminum. The puddle the leak leaves is the size of a coffee cup ring left on a table. It's not really bad, but I don't like puddles in my drive way. I discovered the leak over the summer just before I was towing an 8000lb trailer out of town so I bypassed the core. Winter set in and I wasn't going to drive around without heat so I hooked the hoses back up. I know replacement is the correct way especially since this is my almost forever truck, but if the bars tabs plug the leak, I'm fine with that for now. Btw, with a leaking heater core, is there a change it could split open and overheat the vehicle while towing in hot conditions? That would be my main concern being stranded. Of course I could always carry a bypass hose and extra coolant.
 
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Messages
159
Location
Colorado
https://barsleaks.com/product/radiator-stop-leak-tablets-hdc/ GM relabeled part number 12378255 [/quote] This. They work. Used them for years to stop slow leaks.[/quote] I agree barsleaks tablets work for me. I have used them for over 20 years in different vehicles and they stop the leak or slowed it till I got repair. There are limitations as quoted on tablet's backside,"6.If leak persists, a second application may be necessary. One package treats systems up to 3 gallons. ". Note that second application may be required. No mention of additional applications. It does turn out Dex-cool turns coolant brown but has not caused any harm or decreased effectiveness. Friend had a bad radiator leak with limited success and he plugged heater core. Put in at least 5 successive loads. Blames the company to date and tells everyone what a bad product it is. They have excellent customer service with email contact and 800 number. I used another product of theirs which did not work successfully and I called. They sent me the tablets quickly, maybe overnight but can't remember for sure, and at at no charge. Turns out out it was antifreeze related but not any product problem either. Long story there, maybe longer than this. Think I like them a lot? It takes me a long time to type something Like this. One finger and many mistakes. As others say not an employee and never received money. Nothing will stop a leaking radiator pierced by a bullet.
 
Messages
1,038
Location
Minnesota
In the late 60's I had a '65 Pont GP 421 and while traveling between Phoenix and Dallas, I blew off a heater hose with out knowing it right away. I remember coming over a hill at a good clip with Lordsburg just ahead and seeing a New Mexico trooper at the side of a vehicle that he had pulled over. As I dropped speed he turned and watched us approach and then just raised his arm and pointed at us as we went by. While watching him in my rear view mirror I saw the plume we were leaving behind and a look at the temp gauge showed it was about pegged at 250F. I swung into an old truck stop and noted a poor idle as I shut down. We did the hose repair and then while idling and adding water noted bubbles in the radiator fill=oh oh. There was a 16oz can with a pop top of a product that the station operator said that the truckers felt was good that was probably somewhat like that Alumaseal as it looked like a silver slurry. Anyway, I figured probably a blown head gasket and worth a try as a gasket on a bus from El Paso would hold us there. So in it went and after a bit the idle smoothed out and we gingerly drove around and as it did ok decided to head down the road and try for El Paso. Well, it hung in there and so lets keep going and we did make Dallas ok. Then, since it was doing ok over a few days in Dallas, let try for Minneapolis. Anyway that 'chemical repair' hung in there ok as my wife wrecked the car a couple years later and even as that engine lived more years transplanted into a '67 Firebird. You never know sometimes.
 
Messages
159
Location
Colorado
I had a friend/coworker that swore by Alumaseal and after using for years, it plugged his heater core. This was in early 90's and he took car in for repairs. I was present when he called the company. He was told to mail in the repair receipt. They paid.
 
Messages
10,469
Location
Cincinnati, OH, USA
Originally Posted by monster1
Thanks for the replies. I've confirmed that the tank is aluminum. The puddle the leak leaves is the size of a coffee cup ring left on a table. It's not really bad, but I don't like puddles in my drive way. I discovered the leak over the summer just before I was towing an 8000lb trailer out of town so I bypassed the core. Winter set in and I wasn't going to drive around without heat so I hooked the hoses back up. I know replacement is the correct way especially since this is my almost forever truck, but if the bars tabs plug the leak, I'm fine with that for now. Btw, with a leaking heater core, is there a change it could split open and overheat the vehicle while towing in hot conditions? That would be my main concern being stranded. Of course I could always carry a bypass hose and extra coolant.
Adding-NAPA is the place to buy them, 6 tablets cost $3.99, you'll probably need 12 (my XJ has a 12qt/3 gallon system, Bar's Leak says 2 tablets per gallon). Since they're ginger root, they disintegrate into a fine dust in the antifreeze, and jam up small leaks-but will not block a heater core or other small passages. Unfortunately, in my case, they don't last forever.
 
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