Coolant question, converting from universal green back to hoat

[02kj]

I was reading that mixing the universal green with hoat can cause sludge, well when I bought mine it had the green and when pulled apart for rebuilding the heads it definatly had some sludge, I'd like to convert it back to hoat but don't want to create even more sludge in it. Should I have a coolant flush preformed and then put the hoat in it or would I be okay just draining it and refilling?

 

[Porkchop]

Flush it well and only use HOAT there are other issue by not using HOAT besides slug.

 

[dude1116]

Yep go with a flush. It's quick and easy.

 

[02kj]

A professional flush or would a driveway flush be sufficient?

 

[profdlp]

If you're comfortable removing some radiator hoses and have something capable of pumping enough pressure through the system to clean it out right, go for it. I had mine done at a shop and was happy with the way they really cleaned it out from end to end.

By the way, when I got my Jeep last May it had a mix of who-knows-what in there. The guys at the shop were amazed at the clumps of cottage cheese looking stuff they were flushing out of the radiator and everywhere else. They even removed the overflow tank and cleaned it by hand to make sure they got it all. If you like having heat in the winter and wish to avoid a very expensive heater core replacement, get it done right - no matter who does it.

 

[LibertyTC]

The dealer has a flush machine and can perform this task easily at a reasonable cost.
The dealer will also ensure the correct coolant will be used!
Hoat should be flushed every 5 years minimum.
When I requested that the coolant be good to -55c they said no problem, but asked where are u going to the North Pole? I replied close..Northern Alberta in the winter!
I know I don't want to deal with any mess in a driveway, and then also have to safely dispose of old coolant. Got better things to work on than that LOL.