How do I clean a sticky dirty heat exchanger on the coolant fresh water side?

I hope you don't discover why stop leaking was used.

 

Who knows but it is not leaking out any gasoline yet.

When it is clean, I will pressurize it with the hose, which out city pressure is maybe 60 psi. and that is kinda high seeing the radiator cap is 7, I will figure out something.
Well the cap will release the excess pressure.

 

Copper oxide is a weak base, and vinegar a mild acid, so the vinegar might be acting on the oxide layer and carry away

you aren’t gonna close it up and pressurize to 60 psi, the flush is open, so the pressure is not much unless your relief is tiny

 

yeah, its a 1/4" copper tube coming off the rad cap.
I figure it will blow off the excess pressure so as not to explode the heat exchanger.

The gasoline is working well.

 

Today, dumped the gas and spray rinsed with hose, then refilled with the vinegar.
The tubes look pretty clean what I can see of them. The upper chamber has a super soft slimy feel of this stuff when putting fingers in filler and feeling around the very top inside of upper chamber.

Will post pics tomorrow

 

Very clean now. Final vinegar soak and spray out, feels clean inside.



The 1/8" drain port, tube is clean, this is in middle bottom of the unit

 

Here they are fixed, and painted with blue Rustoleum