Flushing cooling system with citric acid?

[GG-1]

Hello All!
I'm hoping some of you could share your experience flushing the radiator and block with a citric acid solution. The 383 in my 1967 Fury(GG) is still excreting brown water even after several flushes with just water, and one with an off the shelf STP flush product added.
My radiator flushes clear by itself, but when it circulates through the block the water is still coming out brownish. I was told that the radiator was re-cored when I bought her 2 1/2 years ago.. but it seems like maybe a lot of stop leak may have been added at some point.. IDK for sure.. but the engine did sit for several decades without coolant changes. There are no signs of coolant leaks, internally or externally... and I don't want to create any! I've read conflicting accounts on the interwebs about citric acid. The standard protocol seems to first "degrease" the passages with a Dawn or Shout flush, drain, then a citric acid solution of 1 lb of citric acid dissolved in a gallon water, into the radiator, then fill the rest with water, and run/drive car for 15-30 minutes. Some say drive it longer, then flush. A few out there claimed this weakens water pump gaskets, etc. and caused leaks. Many others say it works great. So I ask you kind C-fellows-- any advice/ testimonials?
Thanks, Alex

ps. Also, where do I get an adapter tee/flush kit for garden hose attachment to the upper radiator hose. I want to run water in through the water pump housing(snugly fit) to pressure flush the block.

 

[The Goose]

I always heard horror stories about bursting hoses after using a rad flushing treatment. Never happened to me because I've only used cascade. It kills everything in the cooling system and its dishwasher safe LOL !!! We use it in our service dept at the CAT dealer where I work. It goes after that white hard water crust like a mad man.

I've seen the T's at most do it yourself auto parts stores. Car Quest or a real Napa should have it.

 

[GG-1]

I always heard horror stories about bursting hoses after using a rad flushing treatment. Never happened to me because I've only used cascade. It kills everything in the cooling system and its dishwasher safe LOL !!! We use it in our service dept at the CAT dealer where I work. It goes after that white hard water crust like a mad man.

I've seen the T's at most do it yourself auto parts stores. Car Quest or a real Napa should have it.

Thanks Goose,
I'll look into the Cascade treatment. No spots!

And will pick up the adapter to block flush. Easy enough.

 

[The Goose]

Good luck. It's the stuff in the shiny green box, it's powder a not liquid.

 

[70bigblockdodge]

Dishwasher soap works well and no sudsy mess everywhere like Dawn. I have used the Napa brand liquid stuff and the No.7, two part powder stuff ( which I think is just dishwasher soap and some baking soda mix in the small end to neutralize after the flush. I'm

 

[commando1]

None of those Tiger Piss remedies work unless they have circulated through the system for a minimum of 100 miles at operating temperature.

 

[70bigblockdodge]

One thing I do with a dirty system or a new engine is put a lint catch mesh screen, same one you use on the washing machine. Put it in the upper radiator hose held at the thermostat neck, it will trap big rust flakes.

 

[GG-1]

Eeeny meeny miney mo,
Tony the tiger-piss to catch some big frosted flakes with a dryer screen.

Thank you!

 

[The Goose]

Sorry bud. Everyone has a secret tip. All I can say is our power div guys use cascade. It tears up the hard water deposits. If your going to an ELC just make sure the old stuff is 100% flushed. I just use the mix with anything orange stuff as mine is a 1969 150k original everything system. It doesn't overheat but it's nasty inside. Like you're asking about I just fear poking a tiger with system flush. If/when it acts up then I'll go through it. Good luck with the clean out.

 

[stubs300]

I would've never thought to use cascade to help clean the system, it does make sense though. I have used CLR in the past, and like Stan says, take a long drive and get it workin around the system, then flush. Repeat as needed till it's clean.
I don't see why citric acid would hurt the system? The same would hold true with using vinegar as well, the big worry is mixing chemicals like doing ammonia & bleach kinda thing. Good Luck

 

[Gerald Morris]

I'll try the Cascade this spring. Just popped a new Stant superstat 180F in as the last one from Rock opened a little slowly for my liking. This one is quicker, as they usually are. Notice the Hayden 2707 isn't cutting it this spring either, so for the next couple weeks am going back to the straight 6 blade 18 inch steel fan I got w the car until I get the extra $40 to get the 2797. I don't mind it warming up slower once the hot season hits down here.... Mind you, having run naught but distilled water and antifreeze since the last fall flush, I SEE VERY little crud in the cooling system but noticed plenty down by the passenger side front expansion plug when I replaced the rubber one w a copper plug about 6 weeks ago. Next time I do one of those, I'll blast it out w compressed air while I've got it open down there too. I expect plenty garbage down at the rear of the motor, for sure.

 

[Gerald Morris]

I would've never thought to use cascade to help clean the system, it does make sense though. I have used CLR in the past, and like Stan says, take a long drive and get it workin around the system, then flush. Repeat as needed till it's clean.
I don't see why citric acid would hurt the system? The same would hold true with using vinegar as well, the big worry is mixing chemicals like doing ammonia & bleach kinda thing. Good Luck

If one uses only weak organic acids for flushing, it should be fine even if one were to mix say, ascorbic w acetic acid or such. Strong oxidants and any bases amount to sabotage. Even a BUFFERED mixture of sulphuric acid with sodium bisulphate probably would work well, IFF you mind the pH. Plumbers use sulphuric w cast iron pipe often enough. Care is warranted, 2 B sure.

 

[tbm3fan]

I didn't notice if an amount of Cascade was mentioned. If not then exactly how many cups should one use in a system. Since it is time to do three systems on cars, which haven't had engines just rebuilt, I thought I'd give it a try.

 

[bulldogchesty]

I have used this with good results.THERMOCURE™ - Cooling System Flush - Evapo-Rust