Coolant flush questions...
 

In a pinch last winter I used some of this radiator stop-leak. I'm currently replacing the water pump, thermostat, expansion tank and all hoses.

I'd really like to flush the radiator and transmission cooler to get any and all remnants of the stop-leak out.

What can I flush with to ensure that?

On a past vehicle I used Restore and Restore Plus with great results but wasn't sure if an acid & alkaline based flush product would be OK to use on a N62.

Coolant flush questions...
 

The best flush I saw online used I believe dish soap. (and lots and lots and lots of water).

He had a trans cooler failure put oil info the coolant so he needed an emulsifier to remove the oil. I think that would work very well to get out any debris without having enough base or acid to be a concern with the aluminum block.

I would refurbish the transfer pipes when changing the water pump. I have photos from when I did chain guides on m62tu. The ends of the pipes were quite corroded so I figured out a way to attach the pipes to a drill and use scotch bright pad to polish there ends to a mirror finish. I also sealed painted the outside to prevent the corrosion coming back.

https://uploads.tapatalk-cdn.com/202...f11b6fc820.jpg
https://uploads.tapatalk-cdn.com/202...dbe093f81d.jpg
https://uploads.tapatalk-cdn.com/202...3f004caf43.jpg

I also sealed the outside with RTF that's only to make a seal between the paint and the mirror finish that I left bare for the rubber gasket to seal against.

https://uploads.tapatalk-cdn.com/202...70126af67b.jpg
https://uploads.tapatalk-cdn.com/202...1e33c8b29a.jpg

I used an impact socket and Impact adapter to spin with a drill. Worked like a charm.