After 31 (lots of harrowing stories and now up to 39) leaks I bought a $100 pressure tester that works on the Waterleaker tank and cap.

I have a couple of extra tanks that started leaking, detectable with the pressure tester. That aluminum tank sounds compelling.

Also have several caps: 13, 8 and an invaluable 0 PSI which I made and is carried in the van’s misc part collection along with some tape to contain hose leaks. When a leak presents itself, I try to contain it then put on the 0 PSI cap so I can get somewhere to fix the leak conveniently without frying the engine.

Also mounted a coolant pressure gauge in the ash tray as an extremely important measurement of proper/improper coolant system operation.   Also tells me when I forget to put the high PSI cap back on, usually only needed in high temperatures and/or high altitude.

Somewhat miraculously, 323K mile engine.  Light touch on accelerator seems to help, too.

As a footnote, from swimming pool maintenance, I put a thin layer of clear silicone grease on rubber hose water mating surfaces….garden hose washers, coolant hoses, anything with water going through it.  Easier assembly/disassembly and a much better seal.  Do need to tighten then retighten clamps because of of less rubber to mating surface friction.

Cheers, Tom