How to flush cooling system?

[SC Maintenance]

non 2-EHA coolant

2-EHA is an excellent anti corrosion additive, especially for a cast iron block. The issue is using it in an engine not designed for it. ie I would never put it in any in my signature, simply because I don't know.

All Dexcool is 2-EHA I believe. So its had it in there for 27 years. Do you really think another few months matters to the plastic parts? If it were mine I would wait and have everything done at once.

Anyway, if you insist, I wouldn't be in a rush to use anything other than distilled water unless it shows some sign of needing it - ie if the dexcool comes out looking poorly or whatever.

Either way, good luck. My dad owned a couple Park Ave's and loved them.

 

[JHZR2]

What I'm asking is: Would 2 distilled water flushes be good enough, or should I do a chemical/additive/cleaner flush followed by a distilled water flush?

I already own 10 gallons of distilled water.

Are you opening the block drains to get it all out? If so, then two is probably ok. If not, may take a bit more…

 

[Lubener]

I will probably change the gasket and elbows eventually, but I can't deal with that now. For now I just want to flush and replace coolant with good non 2-EHA coolant.

I would atleast change out those plastic elbows with metal ones when you drain the system. They are not difficult they get very brittle and could leave you stranded with an over heated engine. Get an oil analysis to see if potassium and sodium levels are present in the oil.