Liquid Aluminum, Pelletized, or Tablet Stop Leak for Heater Core

I guess it's not recommended to use this solution for a leak in the cooling system, I can understand why & I'd rather not, but I'm in a pinch, & windows are unsafely constantly fogged... I'd bypass the heater core, but I need heat, it's the winter

My cooling system needs a complete overhaul anyways... A/C hasnt worked for atleast 10 years, I'll be overhauling the HVAC system (heater/evap cores & foam seals), radiator, water pump, hoses, etc... Summer project

I've read many mixed testimonies... "NO NEVER USE", "Been using it for years", "It made it worse", "It saved my life!", etc... So, can't decide which additive to go with to seal up the leak in the heater core... Definitely going with "Bar's Leaks" line...

Liquid Aluminum... Pelletized Heavy Duty... or Tablets...

I'm leaning towards Aluminum, but curious if anybody has opinions which one would be better/appropriate for this application... Also, would it be better to flush out the heater core first, in the event its clogged??

What year? On a pre97 it should be a weekend project.

If you do add stop leak, what is your plan for getting out of the block later?
Personally I am not a fan of magic in a can. Once we had a guy in a van selling miracle cures come to the shop. At the time I was working on a minivan with blown head gaskets, if you pulled the plugs, and got all the coolant out of the chambers it would run great, for about three minutes, when the chambers would again be filled with coolant. So the snake oil salesman wants to demo his junk, promising everything from better compression to +20 points on your kids SAT's. Well he mixed potions like a mad scientist, adding a little bit of miracle cure to every fluid in the vehicle. Started it up, and it ran great for about 3 minutes, when it started bucking and knocking. Never seen an old man run back to his van that fast. Lol

Woops, its a 98... Do you mean they HVAC R & R is a weekend project?... I've mentally prepared for that... I'm not intimidated by the work involved (professionally getting any remaining freon, removing the dash, blah blah)... Got the tools & garage, just lacking money... & if i tear into it, I'm replacing the most of the system I can, which equals more $$

"+20 points on kid's SAT's", haha... As for removing it from the block in the future, not quite sure... Bar's has a cleaner...



... but I dont know how legit/thorough it is

This is my main concern, long term effect & residual effects on the block... & I'm also leery of using a "coagulating" agent in my engine's "arterys"... If I cant get a "magic in a can" type product, would a power flush of the system be an option??

Are you sure that the heater core is leaking? In your post you also propose that it could be clogged. Before going the Bar's route i would veriy the cause of the situation. Is it a blend door problem? What temps are you getting on the dash? If flushing, can you get it into a warm place to do the job?

xjwisconsin said:

Are you sure that the heater core is leaking? In your post you also propose that it could be clogged. Before going the Bar's route i would veriy the cause of the situation. Is it a blend door problem? What temps are you getting on the dash? If flushing, can you get it into a warm place to do the job?

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Windows constantly fogged in a oily film... I've cleaned with auto glass cleaner, "invisible glass", at least 20 times in the past few weeks, & keeps coming back... Although if I run the defrost on hot, on full blast, 10-15 minutes later, the center of the windshield clears up, not where I need to see... If I leave it for a little while, engine off, ALL the windows get completely fogged... If I run cold defrost, its semi-helpful, but I'm effin freezing... If I dont run at all, it slowly fogs up & I have to open the windows because smoke billows out of the defrost vents, & I'm EFFIN FREEZING... clearly visible when blower is off, not thru the adjustable occupant vent, but the vent above those, & when switched to window defrost, my windshield fogs up

...There's sweet coolant smell, passenger side foot well carpet padding is wet, heat blows hot as the bowels of hell, cold side blows "cool-ish", but like I said A/C's has been non-functioning for 10+ years, & she's running abnormally hot, 210-212* per dash gauge...

Heater core??

I was thinking to flush the core, just to clean out any crud or corrosion, just in case there is something built up in it, & then I add the hole sealer, adding to the block

As for somewhere warm to flush, yes... I have a garage, plenty of tools, familiarity of how to do it, & unfortunately time to do the overhaul, just lack of funds... Why do you ask??

I used both Bar's and Alumaseal numerous times over the years and never had a problem. My suspicion is that these snake oils can cause problems in vehicles that are neglected to begin with. My guess is that if you put these blocking agents into vehicles that are full of crud already, you may have problems. I have always stayed on top of my cooling system maintenance. I believe this is why I've never had problems with these remedy products.

I was particularly grateful when Bar's leak cured a leaking heater core on my wife's '89 Mercury Sable. The car was about five years old or so and the I would have had to disconnect the evaporator to replace the heater core. At that point in time, R-12 was going for an extraordinary amount. The Bar's leak saved me a ton time and money.

There's my .02.

Only asking as I figured we should all be on the same page... that said, I would deff agree that you have a core leak. As ar as flushing, I think your right that any bits that might be in the core already are going to be an even bigger concern if you add the liquid. Your probably going to want to flush the entire system at that. I know how it is to be short Im laid off right now and it sucks to have tons of time and no cash... Unfortunatly it seems like your best option is going to have to be the Bar's. For what its worth, when I flushed my core out a month ago I found that a lenght o 1/2 and 3/4" pex tube will fit nicely into the tubes goint to the core, thus keeping all flushing fluids contained. I ran two gallons of white vinegar through the core to try and remove scale and deposit.

you don't need to discharge the AC system to change a heater core, but on the 97+ models you need to remove most of the lower dash. search for "heater core writeup" here on naxja and you should come up with at least a couple detailed how-to's on the subject. make sure you are following one that is for a later model like your XJ as on the earlier ones the procedure is different.

I would definitely back flush the heater core, Radiator, and and flush the entire system first.

I would be tempted to rig up a special pump, and hot plate and a pan of HD sealer (like the liquid glass block crack sealer)/DI water mix and circulate only in the heater core. You would need a special pump, high temp, about 15 PSI back pressure tops.....(stuff I already have).

Then flush it COMPLETELY!!!!, and try it out with 50/50 mix DI water/coollant-antifreeze.

If it still leaks then add the milder, bars leaks product or your choice (copper, aluminum or pellets, they all have the same fiber in them) and run a good 1-2 hours while you pray to Jeep deitys of your choice for it to work! LOL.

210-212 is definitely not running abnormally hot/ pretty normal actually

volaredon said:

210-212 is definitely not running abnormally hot/ pretty normal actually

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When it is -12 outside (I think he said), I would disagree!!!!

McGR96 said:

I used both Bar's and Alumaseal numerous times over the years and never had a problem. My suspicion is that these snake oils can cause problems in vehicles that are neglected to begin with. My guess is that if you put these blocking agents into vehicles that are full of crud already, you may have problems. I have always stayed on top of my cooling system maintenance. I believe this is why I've never had problems with these remedy products.

I was particularly grateful when Bar's leak cured a leaking heater core on my wife's '89 Mercury Sable. The car was about five years old or so and the I would have had to disconnect the evaporator to replace the heater core. At that point in time, R-12 was going for an extraordinary amount. The Bar's leak saved me a ton time and money.

There's my .02.

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Good to hear... I thank you for your .02!

xjwisconsin said:

Only asking as I figured we should all be on the same page... that said, I would deff agree that you have a core leak. As ar as flushing, I think your right that any bits that might be in the core already are going to be an even bigger concern if you add the liquid. Your probably going to want to flush the entire system at that. I know how it is to be short Im laid off right now and it sucks to have tons of time and no cash... Unfortunatly it seems like your best option is going to have to be the Bar's. For what its worth, when I flushed my core out a month ago I found that a lenght o 1/2 and 3/4" pex tube will fit nicely into the tubes goint to the core, thus keeping all flushing fluids contained. I ran two gallons of white vinegar through the core to try and remove scale and deposit.

Click to expand...

Thanks, appreciate your advice... I definitely want to do things right, & I know adding a stop leak additive isnt the best solution, but unfortunately I don't have another vehicle & it's getting to be unsafe driving it... Hoping for a quick band-aid till I can over-haul the whole system, which I've had plans for

GREAT idea with using Pex tubing!!... Got a bunch of left over rolls, the crimp on clamps, & the tool set to crimp with... I might try something along those lines... Did you just push the tubes inside the core tube??

GrimmJeeper said:

you don't need to discharge the AC system to change a heater core, but on the 97+ models you need to remove most of the lower dash. search for "heater core writeup" here on naxja and you should come up with at least a couple detailed how-to's on the subject. make sure you are following one that is for a later model like your XJ as on the earlier ones the procedure is different.

Click to expand...

I think I read all write-ups there are, & not just on , but jeepforum, cherokeetalk, & even a PDF with awesome pictures :read:... Got the best ones bookmarked & ready for reference, & also have that sorry excuse of a repair manual, Haynes, for when the time comes... & yes, definitely 97+...
My post may be low, but I'm not that much of a newb

Ecomike said:

I would definitely back flush the heater core, Radiator, and and flush the entire system first.

I would be tempted to rig up a special pump, and hot plate and a pan of HD sealer (like the liquid glass block crack sealer)/DI water mix and circulate only in the heater core. You would need a special pump, high temp, about 15 PSI back pressure tops.....(stuff I already have).

Then flush it COMPLETELY!!!!, and try it out with 50/50 mix DI water/coollant-antifreeze.

If it still leaks then add the milder, bars leaks product or your choice (copper, aluminum or pellets, they all have the same fiber in them) and run a good 1-2 hours while you pray to Jeep deitys of your choice for it to work! LOL.

Click to expand...

You know I was wondering if I could go about circulating the sealer only thru the heater core, instead of the whole system... Problem is I dont have a special pump, & that would circulate the water/sealer mixture at high temps & with pressure...



...would that work??

Ecomike said:

When it is -12 outside (I think he said), I would disagree!!!!

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:shiver: not exactly... hasnt dropped below mid 20's so far, & its been an abnormally warm winter so far... I know 210-212 isnt all that abnormal, but thats now, in the winter... Couldnt go wheeling last summer, because it would overheat at trail speeds

Thanks for all the info ya'll:exclamati:exclamati

I just slid the pex tube into my rubber hoses. No clamping required. They fit nice and snug. Good Luck.

The BARS-LEAK is the best !!! Don't use the copper or aluminum seal, because when the head cracks or the head gasket blows, all that metal ends up in the oil=pan.... Guess what that does to the cam and poor rod bearings.... Just ask me how I know.

Just to clarify I'm not calling you a newb just informing you that you don't need to rip the AC system apart to get at the heater core It's been done plenty of times without pulling the passenger side of the dash as well, just trying to help you with ideas of what to search for :cheers:

You would need a pump that is rated for what ever fluid temperature you chose to circulate the sealer at. Not sure if the liquid glass block sealer needs heating? Check a bottle label to see. But plastic pumps are not typically going to handle more than 120 F. For 160 F or higher you would need stainless steel or bronze with a shaft seal rated for for the high temp service on the pump. If you don't need to heat the solution, that pump should work, but be careful the pump pressure (what ever pump you use) does not go over about 15 psi max, or it will make the leak at LOT bigger!!!!

This seems to indicate the need for a lot of heat, and prior and final flushing draining and drying...

http://www.barsproducts.com/tech/1100_tech.pdf

So you may not want to go this route after all?

Might just flush the ratiator, heater core, block, and try the mild duty brown pellets with 50/50 old style Green antifreeze that lists sodium silicate on the ingredients label. Do not use the new style antifreeze coolants!!!!

forged said:

The BARS-LEAK is the best !!! Don't use the copper or aluminum seal, because when the head cracks or the head gasket blows, all that metal ends up in the oil=pan.... Guess what that does to the cam and poor rod bearings.... Just ask me how I know.

Click to expand...

If it gets in the oil, it won't matter what brand it was, metal additive or not IMHO. The fibers, and silicate, and EG and water will fork up the engine pretty fast anyway.

I wouldn't use a stop leak for something like this. Usually when a heater core goes out, it dies via one of two methods. Either it develops a hairline crack at a stress point or crummy solder/braze/weld joint, or it corrodes out from the inside until it is paper thin in one spot and then a tiny pinhole leak forms. If it is the former, a stop-leak can work I guess. But if it's the latter, you are pretty much driving a ticking time bomb, when the rest of that paper thin section blows out, you suddenly have a significant cooling system leak and it will be under mild pressure. When my radiator hose let loose it was not a fun experience but at least it was under the hood.

Also, :wave: welcome to the "driving a 98 with a bad heater core in a new england winter" club! I have a roll of shop towels in my passenger seat and end up driving with the window open 2", it just has to make it till I have enough time to finish fixing one of the other jeeps, then I am pulling the dash apart to replace the core.

what about bypassing the heater core and adding an electric heater to get you by?

GrimmJeeper said:

Just to clarify I'm not calling you a newb just informing you that you don't need to rip the AC system apart to get at the heater core It's been done plenty of times without pulling the passenger side of the dash as well, just trying to help you with ideas of what to search for :cheers:

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No, I know you didnt... & I understand what you were trying to say... Just trying to elaborate that I am VERY investigative, google is my homie, along with "site:naxja.org"... Coming to the conclusion that it was my heater core, & the possibilities was thanks to a few days of searching & comparing symptoms

As for not having to remove the dash... From what I know, it's basically one big piece (under the little pieces, I.E; glove compartment, center pieces, gauge cluster, steering column, etc)... Unsure what you mean by "passenger side"... Isnt that where most of the HVAC box sits?

I saw one, where he hacks up the HVAC box to maneuver the core out... I'd rather not cut "access/maintenance" holes in the HVAC box, & in turn, maybe making things harder than they should be... When I do remove it, I also want to replace the evaporator core & foam seals

Thank you tho, I appreciate ya looking out & pointing out other viable options :thumbup:

Ecomike said:

You would need a pump that is rated for what ever fluid temperature you chose to circulate the sealer at. Not sure if the liquid glass block sealer needs heating? Check a bottle label to see. But plastic pumps are not typically going to handle more than 120 F. For 160 F or higher you would need stainless steel or bronze with a shaft seal rated for for the high temp service on the pump. If you don't need to heat the solution, that pump should work, but be careful the pump pressure (what ever pump you use) does not go over about 15 psi max, or it will make the leak at LOT bigger!!!!

This seems to indicate the need for a lot of heat, and prior and final flushing draining and drying...

http://www.barsproducts.com/tech/1100_tech.pdf

So you may not want to go this route after all?

Might just flush the ratiator, heater core, block, and try the mild duty brown pellets with 50/50 old style Green antifreeze that lists sodium silicate on the ingredients label. Do not use the new style antifreeze coolants!!!!

Click to expand...

That was my main concern, would the pump handle the heat & would it be able to circulate the additive without itself clogging up... I'll be looking into pump rental options, & definitely not exceeding 15 psi

Now, that product you linked is a head gasket repair solution... I would assume that sees a lot higher temps & pressures than a heater core does, initially needing high temp when applied, to "bake" it on, so to speak...

Would using a lighter duty sealer be less prone to building up in unwanted areas, like within the block?.. "New style coolants", you mean those orange ones?

Again, thanks for all your info!

kastein said:

I wouldn't use a stop leak for something like this. Usually when a heater core goes out, it dies via one of two methods. Either it develops a hairline crack at a stress point or crummy solder/braze/weld joint, or it corrodes out from the inside until it is paper thin in one spot and then a tiny pinhole leak forms. If it is the former, a stop-leak can work I guess. But if it's the latter, you are pretty much driving a ticking time bomb, when the rest of that paper thin section blows out, you suddenly have a significant cooling system leak and it will be under mild pressure. When my radiator hose let loose it was not a fun experience but at least it was under the hood.

Also, :wave: welcome to the "driving a 98 with a bad heater core in a new england winter" club! I have a roll of shop towels in my passenger seat and end up driving with the window open 2", it just has to make it till I have enough time to finish fixing one of the other jeeps, then I am pulling the dash apart to replace the core.

Click to expand...

Replacing it is inevitably what's going to happen, just need to get thru winter now, & see out the windshield when driving... Might just have to bypass, bundle my ass up & suck it up till I tear into the dash

Yea, hose & radiator ruptures are to some degree, manageable... Only had to deal with "ok how do I get home without over heating?"... But in cabin, DO NOT EVER want to deal with that... Possibly spraying out of the window defrost, ruining dash electronics, & puddling at my feet...

haha, buddy of mine gets in the other day & I had a roll of paper towels & a couple rags on the seat... "damm, how much of a slob are you, you need a whole roll & rags at your side?!"... me: "shut up, clean your side of the windshield"