Prestone AS661 Engine Block Stop Leak with Kevlar, 16.5 fl. oz.

As I drove my 1993 Chevy S10 pickup, I began to smell the familiar odor of an antifreeze leak. Sure enough, when I pulled over, I noticed antifreeze leaking from below my engine block. I realized it wasn't any of my hoses and that it might be coming from one of the freeze plugs.I didn't want to use up my AAA so I researched and spoke to my mechanic. He recommended a STOP LEAK. I found a Pep Boys nearby and I saw a few products claiming the same thing, to stop leaks. I purchased the PRESTONE Engine Block stop leak for $11.I followed the instructions by first putting in the pellets into my radiator followed by pouring the two liquids included simultaneously. Following the instructions, I ran my car for 20 minutes at least and it completely stopped the leak. Although there are no problems, this is a temporary fix only, but it does buy me time and also save me from using up a tow. I HIGHLY recommend this product!

I bought all three versions of the Prestone sealer with Kevlar ( head, block, etc.) to use in my tractor. I never got to use any of it, however. What the instructions do not tell you is that, if stored in an unheated garage that can drop below 32 degrees F, the clear liquid in the sealer expands, and ruptures the clear plastic container. What a mess ! I had to throw all 3 containers out. I'll buy some again in the Spring !

I bought this product last year for a 1995 Ford F150 with a 302 v8. Unfortunately the block is cracked, and before I bought this, my engine burned quite a bit of coolant and blew lots of sweet smelling white smoke out the tailpipe. I followed the directions exactly on the bottle and started the engine. The smoke continued to blow for about a minute before it completely vanished. That was over a year ago now. The engine no longer loses coolant, and I drive the truck as a daily in Alaska. This literally saved my block, and continues to do so without any repeat applications. I think my favorite feature is the fact that it does not gel up the coolant or turn it viscous in any way. Very impressed! Thank you Prestone!

This product does not work on my car. It raised the coolant temperature, increased coolant pressure break through the cap, and spray the coolant everywhere.

Finally!!! A coolant leak product that actually works!!! Over many years and many engines, I've tried every product ever offered for sealing minor leaks somewhere in the cooling system (not the water pump weep holes, of course). They have all been found to be, well...crap that did nothing to help the problem. Nothing before this has ever done any good at all, and no one I know has ever successfully plugged a pinhole/crack leak with other products. Boys, I'm here to tell ya that I did the Happy Miner's Dance after I determined that Prestone Triple Seal had actually done what they claimed it would do!!! Glory Halleluja...never thought I'd see the day. Use it...IT WORKS!!!

It clogged my cooling system on my BMW, i had to replace it for over $900.Don't buy