




🛡️ Seal the deal, skip the shop—engine leaks don’t stand a chance!
ACDelco GM Original Equipment Cooling System Sealing Tabs deliver a high-viscosity, one-component RTV sealant engineered for quick, precise application on multiple engine components. This air-cure formula withstands oils, coolants, and corrosion while being oxygen sensor safe. Trusted by professionals and DIY enthusiasts, it enables immediate refilling post-application, ensuring fast, reliable leak repairs that save time and costly shop visits.








| ASIN | B0026JK8C8 |
| Best Sellers Rank | #5,044 in Automotive ( See Top 100 in Automotive ) #1 in Automotive Replacement Engine Cooler Accessories |
| Customer Reviews | 4.6 4.6 out of 5 stars (1,171) |
| Date First Available | April 14, 2009 |
| Exterior | Machined |
| Is Discontinued By Manufacturer | Yes |
| Item Weight | 1.12 ounces |
| Item model number | 10-108 |
| Manufacturer | ACDelco |
| Manufacturer Part Number | 10-108 |
| Model | AC Delco |
| OEM Part Number | 12378255 |
R**R
Great product. Highly recommend
I have a 2013 Prius, 3rd generation . 210,000 miles. It had been running perfect, when it developed very rough engine noise and severe shaking from time to time when starting. Once underway the car ran normal. A couple of well reviewed mechanics were unable to figure out the cause of the problem. One even said the engine had something lose inside and wasn't worth fixing and should be sold for junk. That made no sense to me. Said he would give me $500 for the car as a trade on one of the used cars he had for sale. The other mechanic said he was certain the head gasket was not leaking (I suspected it was the problem until I got that advice) The check engine light came on and the code said the problem was with the #2 cylinder. I decided to use the internet to find an answer. Turns out this generation of Prius often suffers from the head gasket leaking a bit of water often into the number 2 cylinder. It's a somewhat common problem at around 200,000 miles. Number of options. 1, replace engine with a new or rebuilt or use a low mileage engine from Japan. 2. replace the head gasket. Costly options on an older car with lots of miles. fortunately, I came across a retired mechanic who was aware of the problem and suggested as a first and least costly option, I buy and use this AC Delco product to try and stop the leak. Said he used it on his own car with good luck. Said he was into the second year after using it once and no leaks. I bought it and put into the engine per the instructions. It has now been over 1000 miles since I used the product, only one application, and NO PROBLEMS!!! Talk about a cheap and effective fix. Plus it pin points the cause of the problem. So much for considering top mechanics as the last and best word on my problem. Two lessons learned. 1. This a great product so far. If problem shows up again I will just repeat the fix and take from there. Could not ask for more. 2. The internet is wonderful tool to use to help solve a problem, if only you will take the time and effort to use it fully.
J**N
The best product for stop leak!
These work awesome! Do not bother with the other stop leak products!! I used a few of these to stop a leak in a 2005 Honda Element heater core months ago for a broke friend. Saved them a $800+ shop bill. Stopped the overheating issues due to coolant loss. Excellent product!!!
A**R
These are Effective at Stopping Minor Leaks in The Cooling System
These are Effective at Stopping Minor Leaks in The Cooling Systems Of Vehicles. Follow The Directions!
A**E
Fixed small radiator leak
2014 Sierra - I had a very small radiator leak that I could smell but it did not drip enough to get to the ground. This fixed it, no longer smell it and quit losing antifreeze.
C**B
It works 90% of the time 60% of the time for me
Worked for me within a 20 minute drive, I have a turbo LS truck and put in a new radiator and water pump and hoses and had a small but annoying leak I could not find for anything! these things arent magic in a bottle but its a really cheap way to try the easy way out and if not then oh well you are out a couple minutes and couple dollars and keep going forward….
L**.
Great price
Great for radiators! It's very beneficial for the operation of your vehicle. Recommend using these ever so often
E**R
Worked great
Stop small leak on my 3.5 honda vtech where the seal was leaking on the water tubing from the water pump to the front housing under the intake manifold... on my sandrail...
C**E
Great product and price!
Great product and price!
S**S
Best product
F**Z
J'avais peu d'espoir car j'avais une bonne fuite du radiateur,mais sa fonctionne a merveille
M**R
اوقف التسرب من اليوم الأول بعد معاناة لسنوات - شفرولية كروز ( يجب طحن المنتج ووضعة في الراداتير مباشرة أو في الخرطوم العلوي الواصل للرادتير لو دورة التربيد مغقلة ) ممنوع تضعة في قربة المياة
A**H
Great
W**Y
Work great best stop leak I've ever used in 60 years !!
Trustpilot
3 weeks ago
2 weeks ago