cleaning atf/stopleak mess out of system?

[kc8adu]

i own a chevy van with 5.7 tbi.
seems the p.o had the transmission cooler leak into the coolant.
seems to have a new radiator and a rebuilt transmission.
the leftover atf and some stopleak junk had plugged the heater cores solid.
i changed the stat and was greeted by the stink of old burnt atf when i removed it.
the radiator has oily brown scum in it as does the overflow jug.
several backflushes opened the heaters up but the scum persists.
lots of dark brown crud came out of the cores when i isolated them and flushed them with a pressure washer and a garden hose.
i was thinking of a good dose of dawn to convince the oily scum to leave during the next flush.
its going to be above freezing here for the next week and thought this would be a good time to do it.

 

[eljefino]

Don't use dawn-- it's way too sudsy!

Use electrosol or some sort of automatic dishwasher detergent. The gel will probably dissolve better than the powder but I'd predissolve the dose in a quart of hot water either way. I was told to use a couple teaspoons but in hindsight should have run way more.

I had to do this fixing a cracked cylinder head to get all the oil out of the cooling system... should have seen the "peanut butter" that was in there to begin with, yuk!

 

[kc8adu]

only thing i would worry about with dishwasher detergent is the chlorine.
what is the concern with sudsy dawn?
i figured to run it a few days and do a total flush.

 

[Tempest]

Quote:

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what is the concern with sudsy dawn?

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Cavitation is my best guess. Not good for a water pump.

You might want to try RMI-25. It is a cleaner that many on this board have used. I am trying it right now with good results.

 

[Chispas]

"You might want to try RMI-25" -

What I like about the product, what it cleans

is floated to the surface of the reservoir.

If you over-fill the reservoir the contaminants

are flushed overboard. (No need to drain, just keep

overfilling)