GM Coolant Pellets
Pro
Joined: Nov 2006
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From: Concord North Carolina
Ive never heard of them? I would say GM reccomends alot of stuff and jacks up the prices because only they produce it. I didnt know they had pellets though. Sealing pellets of copper/aluminum yes but cooling ones? Something to think about. Apparently they are made by the company that makes "Bars Leak sealant".
Last edited by B!@cK 86 V3tt3; Dec 5, 2006 at 07:51 PM.
Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The idea behind them was to prevent or stop minor leaks due to casting porosity in engine components. They technically are called "Cooling System Seal Tabs, p/n 3634621"
A couple of years ago, GM issued a service bulletin to service techs that recommended discontinuing the use of the pellets . I used them one time for a radiator flush on my 92 and it didn't seem to make any sort of difference but I didn't have any leaks anyway.
An old-time trick to stop minor cooling system leaks is to add a can of pepper. Yep, plain old pepper from your spice rack. The pepper grounds expand when soaked in water and as they move around the cooling system and stop up the leaks.
A couple of years ago, GM issued a service bulletin to service techs that recommended discontinuing the use of the pellets . I used them one time for a radiator flush on my 92 and it didn't seem to make any sort of difference but I didn't have any leaks anyway.
An old-time trick to stop minor cooling system leaks is to add a can of pepper. Yep, plain old pepper from your spice rack. The pepper grounds expand when soaked in water and as they move around the cooling system and stop up the leaks.
Thread Starter
Pro
Joined: Aug 2004
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I don't have any leaks. I hate to put that sort of stuff in my cooling system without a good reason. Just flushed it and filled with 50/50 dexcool. I know there is a lot of controversy about Dexcool but the coolant I took out looked fine and the system was clean.
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Le Mans Master
Joined: May 2005
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From: Queensland, AUSTRALIA
Originally Posted by B!@cK 86 V3tt3
Ive never heard of them? I would say GM reccomends alot of stuff and jacks up the prices because only they produce it. I didnt know they had pellets though. Sealing pellets of copper/aluminum yes but cooling ones? Something to think about. Apparently they are made by the company that makes "Bars Leak sealant".
Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The instructions on the cooling sealer tabs recommends grinding or curshing them up before adding to the coolant. The tabs are the size of dice 
and could take a long time to dissolve to where they would work as intended.
and could take a long time to dissolve to where they would work as intended.
Burning Brakes
Joined: Nov 2005
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From: Colorado Springs Colorado
Race Director
Joined: Dec 2000
Posts: 17,551
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From: El Paso Texas
Originally Posted by c4cruiser
The instructions on the cooling sealer tabs recommends grinding or curshing them up before adding to the coolant. The tabs are the size of dice and could take a long time to dissolve to where they would work as intended.
and could take a long time to dissolve to where they would work as intended.Using it in my Caddy 4.9 powered Fiero. So far so good.
Safety Car
Joined: May 1999
Posts: 3,651
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From: Atlantis
Cruise-In I Veteran
I 'think' those pellets are mentioned in the FSM.
Is it possible the 'pellets' reduce the possibly of electrolysis between the iron and aluminum parts encountered inside the coolant system?
Do they affect the 'alkalinity' of the coolant or have any other chemical benefit?
Hope this isn't too far off topic.
I can think of only a couple rubber components that can 'come into contact' with the engine coolant.
1) Water pump seal.
2) Radiator cap seal.
3) Coolant hoses
What minerals are in tap water that will damage the engine or the water pump?
Maybe we shouldn't drink that stuff.
Is it possible the 'pellets' reduce the possibly of electrolysis between the iron and aluminum parts encountered inside the coolant system?
Do they affect the 'alkalinity' of the coolant or have any other chemical benefit?
Hope this isn't too far off topic.
I can think of only a couple rubber components that can 'come into contact' with the engine coolant.
1) Water pump seal.
2) Radiator cap seal.
3) Coolant hoses
What minerals are in tap water that will damage the engine or the water pump?
Maybe we shouldn't drink that stuff.
Last edited by VetNutJim; Dec 6, 2006 at 05:35 PM.
Racer
Joined: Jun 2006
Posts: 408
Likes: 0
From: Elkton MD
Cooling system pellets
The packaging warns against inhaling the pellets as they are a 'vegetable extract' (that's pepper) and will cause respiratory distress. They dissolve readily so that's the easy way to get them all into the system (put them into a quart or so of really hot water and shake).
Having worked in an assembly plant (not Corvette or GM) many years ago, I can verify that every auto left the plant with a dog tur_ in the radiator to 'condition' the seals and prevent leaks. To continue....
DuPont tried to make a polymer equivalent to the 'pepper spray' in the late 60's. It worked well for small leaks so long as the system had good pressure (if you're older than dirt like me, you remember the TV ads with a guy puncturing a can of antifreeze and watching the leak stop - Prestone competing product) but the product exaggerated large leaks or any leak when the system wasn't pressurized. My 1956 Chev was one of the DuPont test vehicles. I had to replace the radiator the year after the test and DuPont stopped selling the product soon after.
I use the GM tablets whenever changing the coolant. I'm not a tree hugger though.
Having worked in an assembly plant (not Corvette or GM) many years ago, I can verify that every auto left the plant with a dog tur_ in the radiator to 'condition' the seals and prevent leaks. To continue....
DuPont tried to make a polymer equivalent to the 'pepper spray' in the late 60's. It worked well for small leaks so long as the system had good pressure (if you're older than dirt like me, you remember the TV ads with a guy puncturing a can of antifreeze and watching the leak stop - Prestone competing product) but the product exaggerated large leaks or any leak when the system wasn't pressurized. My 1956 Chev was one of the DuPont test vehicles. I had to replace the radiator the year after the test and DuPont stopped selling the product soon after.
I use the GM tablets whenever changing the coolant. I'm not a tree hugger though.
