Before I rip my dash completely apart or pay the devil to do it for me to fix a small heater core leak... anybody got any experience with cooling system sealers? Pros/Cons? Preferred Brands or ones to avoid?

Thanks

 

I hate Bars-Leak, but I have used it successfully in the past. If it works it will save you lot of work, problem is it can also 'gum up' the core, radiator, etc., so it is somewhat 'chancy'.

 

Thanks. ya, I'd like to avoid something that will cause me more problems down the road.

 

Understand that for sure. I did use Bars Leak for heater drip on my 97 Dodge Ram, it fixed the leak and I drove it another 3-4 years with no problem before I traded the truck for my vette. But one success doesn't mean it always works out. Good luck with the heater core, I understand that is real PITA job.

 

i have used sealer before, within a year it also stopped my heater core up - on a cross country trip in the winter. cost me a small fortune in emergency repairs! I won't do it again!

 

Do you happen to remember which brand that was?

Bars is claiming that 75% of automakers deliver new cars with it already inside.

 

A sealer could possibly save the day in an emergency. I was 500 miles from home at an out of state race when mine started leaking. I used a tube of Alumaseal (sp?) it seemed to do the job for a while without plugging everything up. In Arizona, you may just try short circuiting the heater core out of the plumbing system.

RACE ON!!!

 

Thanks but despite what you might think... heaters aren't optional in AZ in the winter, especially in a vert.

 

I've used alumiseal for decades. Never a problem. I was a GM mechanic in the 70's. GM had large pellets we called asprin we routinely put in the cooling system after doing any type of cooling system repair. I believe it was even installed from the factory in those days. IMO, those who experienced a plugged radiator or heater core after use of a sealant most likely either used an inferior product or the cooling system had other issues. In my shop days I saw many plugged radiators and heater cores. I don't recall seeing any that could be attributed to the use of stop leak. All were more related to age and neglect. Excess 'bloom' forming on the tubes, rusty/muddy looking coolant, that kind of thing. There isn't sufficiant product in a tube of alumiseal to clog anything but a small leak. Other products are clear liquid. Not likely to plug rows of tubes imo. The concept is for them to form a patch when exposed to air just as the clotting factor in your blood does. It only has a chance to work if the leak is about as small has a pin hole or smaller. The tubes in the radiator and the heater core are comparatively large, and not exposed to air so the stop leak shouldn't be able to do anything there.

These days the debate is around dexcool coolant. It appears that this coolant goes bad very quickly when exposed to air. If a person has a leak, installs stop leak, and air still gets into the system, it appears that the coolant will turn to 'mud' and quite possabley clog things up. With air in the system that would happen whether stop leak was used or not.

Having said that, you can try it for a heater core, but I wouldn't expect to get results you'd be satisfied with. My experience with the stuff is that it will stop or slow a minor coolant leak so you don't have to worry about checking the coolant very often, but you may still get a wiff of that coolant smell. Not acceptable to most when it's inside the passenger compartment. jmo

 

I have successfully used the Barrs powder, not the liquid crap for several year now to seal a badly leaking freeze plug. In fact I keep the powder mixed into my 5 gallon premixed antifreeze jug and use it in all my cars. That way, when I flush the system and add fresh coolant, the Barrs goes in automatically. I think GM added the powder at the factory, I could be wrong.

The freeze plug hasn't leaked in three or four years and the coolant system remains clean

seeya

 

Thanks all for the good info. My car has about 44K miles on it. Last year I had the cooling system flushed and soon thereafter could smell that "sweet" coolant smell inside, especially when it's warm outside. Nothing is dripping inside the passenger compartment but I've got to beleive its the heater core. Like y'all probably know the part itself is cheap but the labor charge really bites your wallet. I may give one of these a try for a temporary fix, but I can see a new heater core is likely my best route.

 

There is no doubt about it. Chances are that flush which was probably the first in a long time (if ever) likely dislodged what was plugging that hole. If it is so small that you haven't detected liquid, yet, chances are a sealer will work. Left alone, it WILL begin to leak. They only get worse. You CAN change it yourself. Even I did it.

RACE ON!!!