Severe coolant flush how to

[Sidewinded_idi]

i wanted to share my experience with a severely plugged coolant system in my 92 f350. I just purchased the truck and it would heat up instantly at speed and couldn't use the ac at all or it would overheat, I knew that meant a plugged radiator. I tried all the fancy flushes and nothing worked. I'll explain what did.

-Go to Home Depot and buy a 2 inch and 1 1/2 pipe plug, the kind with a rubber oring sandwiched between two plastic halves that expand with a wingnut. Next buy two gallons of muratic acid but not from Home Depot, Go to a quality hardware or pool store, the Home Depot stuff is only 14. % and doesn't do anything you need the strongest you can get make sure it says 34.5%

- once you have these items plug both the upper and lower radiator ports so it's isolated. Also make sure to disconnect and plug the heater hose coming off the radiator so no acid gets in. The engine.

-depending on severity will dictate your treatment time, once you fill the radiator with the muratic acid straight undiluted make sure to wear a respirator and eyewear as without the fumes were very unpleasant.

- after 3 hours it was improved but still not perfect, I drained and re filled it for another soak this Time for 4 hours straight. After the 7 hrs total of the 100% acid soak my core looked new inside, all the tube scale was removed and it looked great.

- once you drain all the acid make sure to mix up two gallons of water and baking soda and fill the radiator with his solution to neautralize the acid.

-after this was completed I hooked the radiator back online and went to the rust issue. I used a heavy treatment of Two bottles of thermo cure evapo rust treatment,

I drove with the two bottles and the rest tap water for two days and drained. It smells aweful but does it's job, I was able to flush the mixture out and witching a few cycles of straight water everything was crystal clear.

This is a very severe procedure but afterwards inside my heater hoses, radiator everything looked like new. I re filled with fleet pre charged coolant and it stays right in the middle of the temperature range now. Before I couldn't even make it up our local town blvd because it would start to peg the gauge. Now it cools good as new and I saved the cost of what I sure was going to need a new radiator. If yourself is aluminum do not attempt this it only works with the brass cores. And FYI a lot of people said online don't leave the acid in more than 15-30 minutes. For as bad as my system was I had a total of 7 hrs of it plugged and filled with zero side effects.

 

[Black dawg]

I have done this many times, and it works quite well.
I always plan on replacing the water pump, seems like they go a little while and then start leaking after a good acid flush.

 

[MtnHaul]

Straight muriatic acid? Damn!! When I was growing up doing concrete work with my dad we would use muriatic--not sure the % concentration-- at 1:4 ratio with water and that would help eat the top off an exposed aggregate finish. If diluted muriatic acid can eat a thin layer of cement then I would imagine straight would eat through quite a bit more. Glad you found something that worked.

FWIW did you try soaking overnight with white vinegar? I haven't actually tried the vinegar method but have heard good things about it.

 

[Sidewinded_idi]

I have also heard about the vinegar trick, mostly about running a gallon or two mixed with water in your coolant system for a few days, as bad as my radiator was I really didn't see it being strong enough. The first full I did was by accident with Home Depot muratic acid straight and it cleaned the rust off my funnel but didn't touch the scale in the radiator. Once I found out it was only 14% I went to the hardware store and got the full strength 34% stuff. As soon as I dumped it in it started fizzing the scale so I knew it was working. It just took a long time like I said about 7 hrs total of sitting in the radiator.

 

[HS108]

What do you do with all that acid after the fact?

 

[riotwarrior]

I can see this causing untold issues myself.....having experienced a through flush that ended up killing a rad and water pump...

 

[jwalterus]

Straight muriatic acid? Damn!! When I was growing up doing concrete work with my dad we would use muriatic--not sure the % concentration-- at 1:4 ratio with water and that would help eat the top off an exposed aggregate finish. If diluted muriatic acid can eat a thin layer of cement then I would imagine straight would eat through quite a bit more. Glad you found something that worked.

FWIW did you try soaking overnight with white vinegar? I haven't actually tried the vinegar method but have heard good things about it.

I'd try vinegar first myself.

It's a good acid to use to sharpen files

 

[Sidewinded_idi]

What do you do with all that acid after the fact?

I can see this causing untold issues myself.....having experienced a through flush that ended up killing a rad and water pump...

The acid you can dilute with water and dump out, I simply put it back in the original containers and stored it for later use.

And as for untold issues, there isn't any if you do exactly as described, as I directed your isolating the radiator completely. No fluid touches the engine. After it's spotless then you make sure to run heavy doses of water and baking soda through just the radiator to clean out and it neautralizes any left behind acid. I let my radiator sit with the baking soda solution for quite some time. She's still running cool in the middle of 100 degree heat when before I couldn't even run the ac in town

 

[riotwarrior]

I am sure this is marvelous for gaskets and seals....yuppers....pass I will...

 

[austin92]

I am sure this is marvelous for gaskets and seals....yuppers....pass I will...

Maybe tank to core seals. Other than that, it wouldn't touch any seals or gaskets


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[Shawn MacAnanny]

It would be really bad for your oil cooler where there are copper are aluminum together and generally not good for your copper block heater. You can clean copper with hydrochloric but it would usually contain a corrosion inhibitor like rodine to limit copper corrosion. Store bought muriatic would not. It wouldn't hurt many gasket materials but could hurt the metal below the gasket which would cause the leak.

From someone who acid cleans many industrial systems, I would not recommend this, nor acetic acid. The risk for a failure is pretty high doing this. Unless it's your last option before engine replacement. The coolant flush blends offered with phosphoric acid that also contain a surfactant would be a safer route than this as they are also likely inhibited.

 

[SirRea63l]

I believe he is doing the radiator only, not letting the Muriatic cycle through the whole cooling system.

 

[Shawn MacAnanny]

That's much safer for the engine, i thought he was cleaning engine and isolating radiator. I still wouldn't use uninhibited hydrochloric on brass. It could damage the solder. though if you're going through all that with the cost of coolant and risk for a leak I'd just forfeit the $200 for a new aluminum one vs the $50 for acid baking soda, time and risk.

 

[riotwarrior]

Maybe tank to core seals. Other than that, it wouldn't touch any seals or gaskets


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So the head gasket at coolant passages...oil cooler gaskets lower rad hose adapter and thermostat and thermostat gasket and water pump gaskets and seals do not count as havi g edges exposed to this acide...what about oil cooler O rings....there is an O ring on the blocl heater too....

Think I will pass....my personal exp w consumer grade products leads me to beleive this is a potentially flawed methodology and one I would not endorse as a member here nor encourage another member....

JM7.3CW Eh!

 

[austin92]

If you never start the engine, how would it leave the radiator? I think that's the part your missing


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