Where's It Going (coolant)???

[SnowBuck]

Yea, those tablets were standard operating procedure any time we did coolant work on specific GM engines, especially Cadillacs.

Just what are these "tablets" you speak of and where do you get them??? Though I am very hesitant to insert anything in the engine. For instance: radiator leak stop...which ends up "stopping" up more then you bargained for!
A couple of the garages told me to just keep adding coolant as needed - easier and cheaper then opening it up which they say is a can'o worms you don't want to get in to.

 

[TJ Baker]

This is what I used. I have visually confirmed crack(s) in 706 heads in a 2005 LM7. Been well over 6000 miles since I used these and no loss of coolant since.

Edit: I crushed the tabs, mixed with some distilled water and added during a system flush and refill.

https://www.amazon.com/Genuine-GM-12378255-3634621-Cooling/dp/B000QIH3C4

 

[mattbta]

This is what I used. I have visually confirmed crack(s) in 706 heads in a 2005 LM7. Been well over 6000 miles since I used these and no loss of coolant since.

Edit: I crushed the tabs, mixed with some distilled water and added during a system flush and refill.

https://www.amazon.com/Genuine-GM-12378255-3634621-Cooling/dp/B000QIH3C4

That's what I used as well when the second refurb head I received had a small leak on the freeze plug. I probably shoulda crushed em, but I just dropped em in the upper rad hose and followed the procedure to get it up to temp quickly.


Not going to proclaim victory, but I've got about 500 miles and no coolant loss now. I still watch it like a hawk along with my oil pressure. I've got a few more short OCI's to complete and then will send a sample out to Blackstone.

 

[isp5190]

Just what are these "tablets" you speak of and where do you get them??? Though I am very hesitant to insert anything in the engine. For instance: radiator leak stop...which ends up "stopping" up more then you bargained for!
A couple of the garages told me to just keep adding coolant as needed - easier and cheaper then opening it up which they say is a can'o worms you don't want to get in to.

You can get the tablets @ a GM dealer, I also saw them at Advanced Auto in the GM package. I forgot to mention during our research about this, GM recommends adding the tablets anytime the coolant is changed or replacing the water pump or any major component where you loose the coolant.

 

[OR VietVet]

This is what I used. I have visually confirmed crack(s) in 706 heads in a 2005 LM7. Been well over 6000 miles since I used these and no loss of coolant since.

Edit: I crushed the tabs, mixed with some distilled water and added during a system flush and refill.

https://www.amazon.com/Genuine-GM-12378255-3634621-Cooling/dp/B000QIH3C4

@SnowBuck these are the same tablets. Follow instructions as advised. We were just told that any GM engine with aluminum block or heads requires them with the cooling system. We did not question why, we just did it. It is for sure a form of stop leak though.

 

[SnowBuck]

@SnowBuck these are the same tablets. Follow instructions as advised. We were just told that any GM engine with aluminum block or heads requires them with the cooling system. We did not question why, we just did it. It is for sure a form of stop leak though.

These sound like the answer to me. How did you put them in: drop in the surge (overflow) tank or do you need to take off a radiator hose?

 

[OR VietVet]

When I was running shops and we added these tablets, there was still radiator caps on most radiators and we crushed the tablets up and added there. In your case I would add thru the radiator hose.

 

[TJ Baker]

Here are the ingredients if anyone is interested...

 

[SnowBuck]

OK...sounds like what I need since no test shows any leaks!?!?!? Now...If I were to grind them up (maybe a baggie & a hammer) and take off the top radiator hose, and drop it in - How many???

 

[treehan77]

Yeah I smashed em with a hammer. Make sure you didn’t tear the baggie lol