Cleaning the Radiator Question

Turbo Keith

TURBO KEITH
Joined
Sep 16, 2015
So I have some build up on the fins in the Rad , Has anyone used CLR to flush it out ? I know it needs a cleaning just trying this before I have to remove it and take it to a rad shop . Thanks for the help in advance Keith
 
I would think CLR might degrade the hoses and/or gaskets if you run it through the cooling system.

I don't think soaking the radiator in CLR would do any good at all.

Once again, I could be wrong. Others will chime in soon, I'm sure.
 
Last edited:
CLR does work. I use a whole bottle and pour it in let it run for an hour or so or drive it. I don't use it in antifreeze. It will eat the buildup out of the radiator. Afterwards I flush the system real good. Pretty sure it isn't good for the hoses if mixed too strong. You can pull the rad and seal the inlet/outlet and mix clr with a gal of water and pour it in and let it soak.
 
I'm gonna give it a try tomorrow , I'm nit gonna mix it to strong . I will drain all the anti freeze and mix it with water and try that .
 
Think you are just wasting your time & potentially asking for more trouble.

EDIT: You may end up breaking up enough sediment to plug your heater core.

Do it right the first time. Either have the radiator tanks removed & replace the core with a HD core, or purchase a quality replacement radiator from Arizona GN, or ALRADCO.
 
Last edited:
Does your radiator look this bad? In traffic with A/C I saw temps in the 220s.

ad752765b9ecf2b91dbd4c615f8196ca.jpg


Sent from my SM-G930P using Tapatalk
 
My 1990 GT is still running the factory rad and I cleaned it with clr 2 years ago, no issues 48k miles later. I did replace the heater core later but it was already leaking. All the hoses are original except the hoses at heater core. And that radiator was almost completely clogged with the buildup on the tubes. If the heater core is original I would bypass it.
 
Low dollar Band-Aids often result in very high dollar fixes.

Do whatever you feel you needs to be done. It's your money.
 
So I have some build up on the fins in the Rad , Has anyone used CLR to flush it out ? I know it needs a cleaning just trying this before I have to remove it and take it to a rad shop . Thanks for the help in advance Keith
CLR is basically a light cocktail of various acids. Acids eat metals like aluminum, copper and iron. You may do just as well with white vinegar. Or brick cleaning acid (muriatic acid).

I wouldn't worry to much about the radiator. Because it's probably junk anyway. But running acid through everything else? If you want to try to save the radiator that bad, maybe remove it and fill it up with the strongest stuff you want (like muriatic acid). Let it sit for as long as you like. Then rinse the crap out of it. It wouldn't hurt to put some Alkaseltzer tablets in it afterwards with a new batch of water for another hour or 2 before a final rinse and then install.

But I wouldn't trust that stuff (or anything) going through my engine.
 
Yes guys I'm really trying the low cost fix here and yall are all right that it may cost me more in the end but I wont know till I try . I will report back
 
Baking soda instead of alka seltzer. You won't believe how much crap is in cooling system. Friend did his rad off the car a while back and the water was almost milky looking after it soaking a couple of hours. I would never ever leave it sitting in the car or not back flush the whole system for several minutes.
 
I did the F Body radiator upgrade. You lose the oil cooler but it works really well and they can be bought for less than$100
 
Check rockauto, they have a radiator with oil and transmission cooler. That's what I have. The trans cooler needs a different adapter to connect to the lines but other than that it drops in.

Sent from my SM-G930P using Tapatalk
 
I'm gonna give it a try tomorrow , I'm nit gonna mix it to strong . I will drain all the anti freeze and mix it with water and try that .

If the crud is visible at the top, there's a bunch more, closer to the bottom.
Good leak detector...
 
Baking soda instead of alka seltzer.
Yes. Correct, even better! This would make a good neutralizing rinse for any remaining acid before reinstalling the radiator.

But again, I wouldn't let an acidic chemical run all through the entire cooling system and engine. That just doesn't seem right. I would do it while it was removed.
 
I wouldn't let an acidic chemical run all through the entire cooling system and engine. That just doesn't seem right. I would do it while it was removed.

This x100. If you want to treat the radiator with acid of your choice, then pull it and do so. Then run a water/baking soda mixture afterwards to neutralize.
Or, wait, save your pennies, and get a new radiator. You need one.
Don't run an acidic mixture through the entire engine. The chance of something going bad (acid on metal, particles breaking loose) makes it unwise.

You are a valuable poster here, would hate for something bad to happen to your car.
 
Top