CAT Aftercooolers — and whats Real

The chlorine in tap water dissipates within days. I don't think there is enough concentration to affect the metals. Seems someone posted a pic of freshwater flush at the engine raw water strainer, it was very easy to operate. Just closed the sea cock and open a freshwater valve.

By HVAC, do you mean the chiller? If so, isn't it already bonded, and connected to a zinc somewhere through the bonding?
Besides, if you mean that you did that also on an engine heat exchanger, I for one would be interested to see a photo.

I don't know 3406e's but pressure checking an aftercooler is pretty easy on some engines. It insures you don't currently have a leak and I would think gives you some assurance you are safe for at least a few hundred hours. I would think you could install a couple ball valves, a pressure gauge and shrader valve as permanent fixtures and it would take about 20 minutes to test it whenever you want.

Cat has damaged their reputation with aftercoolers issues for years, built with the wrong material.

Flushing the aftercoolers hardly would introduce more problems. It is obvious that the Cat ac's don't last as long as other mfg's. No excuse for the inferior design, all they need to do is copy other designs that last 20+ years. A freshwater flush would only increase the life of any raw water plumbing. The Cat maintenance schedule requires pulling, cleaning, and pressure testing every two years, then replace every six years. You just posted how other mfg's last 30 years, wouldn't you say a six year replacement is a bit short?

That would be good!

the problem is you can not properly test them because they get extremly hot when runnig and there are no test faclities that can preasure test them under the high operating temp That is why they have a scheduled replacment schedule. It is like an insurance policy just suck it up and
change them