Is it something that is dangerus in any way.
I've read about changing the matrix, and it sounds like a very difficult and hard thing to do. Something that should be done at a warm summer day
What about that stuff one can add in the cooler liquid. Some kind of powder to seal small leaks?
The brand is valvoline.
This is liquid. Where should I add it? If you look at my attached pictures in previous reply, (the one where I point), is this the place?
And one more ?, what if there is NO holes in the cooling system. Will it cause a clock somewhere?
should do the job.
usually tells you to add direct to the rad on the bottle but expansion tank (as in your pointy photo) is usually the only option, won't do any harm if there is no leak, just circulates until it hits a leak or you change the coolant.