Radiator flush/cleaner advice

[Sonny]

2 weeks ago I noticed that my radiator only had water in it. Note I've only owned the car ('70 Belvedere 318) for 2 months. I drained about half of it and put 1 gallon of antifreeze in it. It sat until today and drove it to work and back and it overheated both ways. Looked in the radiator and the cores are now full of rusty mud and green rocks. What should I buy to clean and melt this crap? Will just a good water flush do it? I assume I'll need to do both?

 

[khryslerkid]

You can try back flushing the system. Remove the hoses off of the radiator and run water backwards from bottom to top. Maybe removing the radiator and doing this upside down would be best. Run water though the block and water pump until clear. Remove heater core hoses and run water backwards through it also until clear.

Now keep in mind, that if it's been rusting for a period of time, you might be washing out the mud that's been keeping everything together. If the frost plugs are thin, they might start leaking. Same with the radiator and heater core.

If you have caught it in time, use a rust inhibitor along with your antifreeze. Good luck.

 

[PurpleBeeper]

You can use a radiator flush (e.g. Prestone's from auto parts store) and try one of those "back flush T's" you splice into a heater hose and run a garden hose through. Make sure you get plenty of distilled (or at least de-ionized) water to flush out the garden hose water + to mix with your coolant (if using coolant concentrate - 50/50 already has distilled water in it).

If you want to run "water-only", then you can use Water Wetter, Purple Ice, Super Coolant (Lucas). These contain the corrosion inhibitors you'd normally get inside antifreeze. Your engine will run cooler, but you'll freeze up at 32F. They don't really do too much when added on top of 50/50 antifreeze.

 

[Fran Blacker]

I've put a radiator hose connections up on the floor cap on and filled it with white vinegar and let it lay there a few days and then flush it. Do this after what khryslerkid said to do.

 

[Ranger16]

You might need a power flush.

 

[Billccm]

My dad was a machinist by trade, but neighborhood shade tree mechanic on the weekends.

Anyhow, he used Cascade powder for cooling system flush and clean up. His claim was chemical flushes were too harsh and Cascade washed out of the system easily. I've recommended this to many of my motorhead friends, and they are appalled and refuse to do this, yet I have done it for years on my own cars without an issue.

Interesting in Hot Rod magazine last year they had a F150 that the oil cooler leaked into the cooling system. I was glad to see they used Cascade to clean up the cooling system.

I guess ol'Dad was right all along..............

 

[69L48Z27]

Remove the radiator and take it to a radiator shop, have it tanked and checked. If you have that much corrosion you may not get it clean at home.

I took mine out of the 68 GTX this winter. Got it tanked, checked, fins straightened, and hose fitting all bent back into shape. - $35. All clean and I will have no worries this summer.

 

[Pistol Pete]

I ran across this the other day.

https://www.summitracing.com/parts/sum-tc001/overview/

If it works half as good as Evapo-Rust it just might be worth a try.

 

[PurpleBeeper]

I'd have to vote for the vinegar since it's basically acetic acid. Acids react with and remove rust/radiator scale.

I looked at the safety data sheet for Evapo-Rust's "Thermocure"
file://pen3/skretzer/Chemistry%20&%20Formulation%20&%20Patents/Antifreeze%20Patents/File-1446815086.pdf . It looks like EDTA (chelating agent), water and soap with a pH of 6-7, so it doesn't look all that good (but I've never tried it). It's basically "fancy Cascade"