Block sealer - Any suggestions?

[chet445]

Water glass is the answer to sealing the leak without problems later on. It is known as isinglass and can be obtained at you pharmacy. Pour into radiator with a warm engine and drive for 5 miles or so. Will not plug up your radiator but seeks open hole in engine. I have used it two different times with success! Chet

[BILT4ME]

Check your head torque first.

If that doesn't resolve, I recommend the bar's leaks brand. While I am not in favor of pouring stuff into engine blocks, gas tanks, or oils to "fix" a problem, there is a time and place for it.

The bars leaks radiator sealer works very well. I had a cousin that used it in a D8 Caterpillar that had a 3" dia. tree branch that impaled the radiator. They poured in the bars leaks and ran it for another 3 weeks until the new radiator came in.

The other product is bars leaks head gasket repair with kevlar. Another forum I follow really recommends this product.

[Skip Lackie]

When I was a young guy, the old auto repair guys used to talk about 'water glass' or 'egg preserve' as a sealant. Haven't heard that mentioned for many years.

Dwain-
(Even farther off topic) your comment made me root around in the basement, where I found a ~75 year old, unopened can of water glass. It's actually a mixture of sodium oxide and silicon dioxide in water. When exposed to air, it dries to a hard, transparent sealer. It is impervious to petrochemicals. As such, it is/was used as a sealer for concrete floors and packaging. I can see why it would work as a radiator sealer.

[christophe]

Hi Colin, in fact all my spark plugs are clean as I changed them recently but it always seemed to me that the two center spark plugs were a little bit different from the others. Besides, I had recently the confirmation that my car was running lean with the original settings of the carb. Gladly, there is not enough coolant seepage (yet!) to hydro lock the engine. This happened to me once on an other car due to a porous cylinder head. When I tried to start the car, I heard funny noises, like a ticking starter. Result: 3 cylinder liners cracked out of four! I rebuilt the engine and it is still running but it was a costly lesson. Yes, I'll try to avoid the block sealer. This will only be my last choice if everything else fails.
Nice day to all.

[lumpy]

Hi Christophe , try pulling the spark plugs and look for the one that is really clean. If you head is cracked or the head gasket is leaking , it will usually have a very clean spark plug...almost steam cleaned Does the engine momentarily lock upon cranking? - hydro lock? Please try not to use block sealer ,it's a crutch at best...

[Dwain G.]

When I was a young guy, the old auto repair guys used to talk about 'water glass' or 'egg preserve' as a sealant. Haven't heard that mentioned for many years.

[kxet]

I used the pepper a few times,teaspoon worked. You can tell if it starts leaking again, you will smell the pepper.

[TWChamp]

In 1999 I bought a 1928 Model A that had a wet spot in the upper left corner of the radiator. I wish I paid more attention to the brand, but I'm thinking it was KW Block Seal that I used. It was a small granular product that I poured into the radiator and ran it with plain water for a few days. I then drained it and used 50% antifreeze, and it's still dry today. If it wasn't KW, then it would have been Alumaseal.

[christophe]

Thank you very much for all your replies, guys.
I'll have a look at Irontite and KW Block Seal. So far, they don't seem to be distributed in France but they might be in other european countries.
Of course, I will be very cautious with all this and will only use such a product after ruling out all the other possibilities, and only once as said Bill.
I suspected a problem for a long time. I used two different block testers but they did not show anything. Like Lew suggested, I checked for bubbles in the radiator but there weren't any.
I made an oil change in last august, just before going to the Loewy meeting. After roughly a thousand miles done in fair wheather (I assume this rules out any condensation problem), the oil is now brown and after a little decantation, some coolant appear at the bottom. Gladly I never had any oil pressure loss and I was very surprised to see that the oil and the coolant seem to mix fairly well.
I will try to pressurize the coolant to make the leak(s) appear, unfortunately there is no Autozone near me.
John, about the way these products choose to block only what needs to be, I remember Alumaseal said that their product reacted only when oxygen was present, thus preventing to clog unwanted places.
Thanks again for all your comments, I'll keep you posted about this.

Nice day to all.

[jclary]

JMHO, but the only time I'd dump any of those various sludges in the cooling system is if fleeing the zombie apocalypse and it had to run long enough make it over the mountain pass.

If it seems I feel strongly against them, some of the gnashtiest rebuilds begin with a block completely plugged solid with that crappage. I spent two days cleaning a Packard V8 block. No way to know which or maybe all of those products were involved, but once you've seen the inside of a cooling system having had that treatment, no way, no how.

jack vines

I kinda expected you'd respond this way...still funny

[PackardV8]

JMHO, but the only time I'd dump any of those various sludges in the cooling system is if fleeing the zombie apocalypse and it had to run long enough make it over the mountain pass.

If it seems I feel strongly against them, some of the gnashtiest rebuilds begin with a block completely plugged solid with that crappage. I spent two days cleaning a Packard V8 block. No way to know which or maybe all of those products were involved, but once you've seen the inside of a cooling system having had that treatment, no way, no how.

jack vines

[Colgate Studebaker]

I've used Bars Leak for many years and had good success with it. NAPA sells it in a large pellet form that I mix in a coffee cup with a little anti freeze and water mixture. Depending on the size of the coolant system I will use a couple pellets or the entire package. I only use it once and if it doesn't stop the leak, then I go to mechanical repair measures. Jeff made an excellent point to do some testing before just putting something in the system. Hope this helps, Bill.

[jclary]

I bought a 6cyl. Dodge with had a cracked head,it was at a gas station and they told me about head and they had tried lot of crack sealer on it. Owner gave up and left it to be sold. I had access to a good head and put it on. Ran fine, old head had bad crack and used head cured that. But all the stop leak had completly stopped up radiator, had to be rodded out.

Always a puzzle to me regarding "stop leak" chemicals. Whether those designed for cooling systems, or automatic transmissions. I have often wondered, if they will stop up a hole...what's to keep the chemical from plugging up a passage that needs to stay open? I have used some of that "green stuff" to stop leaks in some of my farm implement tires, only to have it mess up the valve for inflating the tire. I have had to remove & clean it so I can inflate the tire.

As a side note, many years ago, I was told that for a water leak in a radiator, an effective short term emergency fix was to buy a small box of ground pepper & dump it in the radiator, and the pepper would stop the leak long enough to get you home. Fortunately, I've not had to test that one.

[kxet]

I bought a 6cyl. Dodge with had a cracked head,it was at a gas station and they told me about head and they had tried lot of crack sealer on it. Owner gave up and left it to be sold. I had access to a good head and put it on. Ran fine, old head had bad crack and used head cured that. But all the stop leak had completly stopped up radiator, had to be rodded out.

[lschuc]

Christophe,
I agree with an earlier comment, for you to retorque the cylinder head bolts first, then drain the oil, fill the engine with fresh oil and then see what happens.
If you can find or get a pressure tester, similar to the one pictured in a earlier response, the that may either show an external coolant leak.

Also, I think that if you remove the radiator cap from the cool engine, then start the engine and let it get warm, after the thermostat opens, you may see air bubbles show up in the top of the radiator coolant. If that happens, it may be a good indicator that there is a cylinder head gasket leak (if not a cracked head... hopefully not!)

Otherwise, contact Josserand at O-One in Bazainville to check out the source of the coolant leak. As you well know, they are familiar with Studebakers !
(you probaly met him in Sepember)