Bar's Stop Leak?
 

I have a pinhole leak in the block of my newly rebuilt I6 coming from a block bolt which holds on my water pump.

Has anyone used "Bar's Leaks" Liquid copper to plug a small leak?

Any success stories? Not so good stories?

i wouldnt use it it can clog up your radiator....best to fix the leak properly...

I would not use it either...I just replaced a plugged up heater core in my daily driver due to using bar's leak..It also plugged up my overflow resevoir as well..Just a nasty black gooey mess everytime you remove the rad cap........It did fix my leak though. :)

Which version of Bar's Leaks did you use?

I am not sure exactly which one I used as it was a few years ago now...I would guess it was the rad and coolant system sealer..All I remember was it was small black pellets..

I wont say I haven't or I wont use Bars Leak in my vehicles, because I have, and under certain circumstances I am sure I would do it again. But it is not a good fix.

For a leak like you describe, I would probably just spend a hour or so and $5 on gaskets to fix it right.

It MIGHT simply be water seeping past the threads, if so, you might just try removing the bolt, and putting some sealer or RTV on the threads.

Might work, but I am thinking maybe the gasket is folded over on the bolt hole...

Try and find a product called "Dikes". Best stuff I've ever used. You can mix it with antifreeze and it won't clog up your system. Plus if you ever decide to fix it the right way this stuff comes out when you drain your fluid.