Cleaning corrosion off a radiator

Any easy tips? There's a bit of green corrosion on the front and back (mostly the back) and a bit of rust...nothing crazy, but I'd like to get the engine bay clean and wonder if there's an easy way to get that stuff off. Battery terminal cleaner? Anything household?

 

Not sure on removal but green corrosion normally is caused by a coolant leak. I'd have it checked before going too far

 

flat black paint, after leak repair

 

I'm sure it needs to be heat-resistant paint...is there any type that should be used, and will it interfere with heat transfer? I'd hate to inhibit the operation of the radiator.

 

+1. Remove and pressure test first. Or pressure test in place. I presume radiator shops can still test radiators.

 

Muriatic Acid (masonry cleaner) will remove oxidation/corrosion completely and make brass absolutely bright.

It was known as Tinner's Flux, and is excellent for prepping radiator repairs when soldering is needed. I've used it often where nothing else would work.

You would need to be VERY careful to protect surrounding areas, AND yourself, and rinse it all completely afterwards. Although 'dilute' it is still a strong acid.

 

The acid idea sounds about like what I need, but it's a little intimidating. I'll look for the fluid leak...I don't see any at the moment, but when I opened the cap, I didn't see any fluid near the neck, so I know it's low. It always seems dry, though, so I wonder what the easiest way to find the leak is.

 

Antifreeze will fluoresce in black light. Or it can be sent out the tailpipe as vapor.

As stated clearly above, pressure test the cooling system. That will tell you if you have a leak. You can buy a tester, or have a local shop test it.

 

The tester kits are expensive...I'm assuming my FLAPS won't do that test for free, right? Anyway, I checked the coolant level, and looking in the top of the radiator...it was wet, but didn't have fluid up to the neck. So I guess a leak is possible. Is radiator Stop-Leak really bad, or is it an acceptable fix? I'm not experienced with fixing those leaks myself, and I can't afford a new radiator. Other than the apparent possible leak, it seems to be in pretty good condition.

I'm replacing my heater in the next week, so I'll probably be draining and replacing the coolant anyway, so if I have a problem, this should be a good time to fix it.

 

I think stop-leak is okay for occasional small 'nuisance' leaks. But not as good as a permanent repair.

As timgr was implying, it's also possible you could have a head gasket leak or a cracked block or head. Stop-leak is unlikely to work in that case. Might be worth doing a compression check - a gauge is not very expensive. Or get someone to sniff-test the radiator for exhaust fumes with a hydrocarbon leak tester.

 

Your flaps may loan you a tester, as far as stop leak, if it were me. I would not use it. When I have used stop leak I wished I did not. It can really gum up the works.

 

Stop leak is intended for emergencies, i.e. to get you home or to a repair shop. Many types plug up heater cores and radiator cores. If you decide to use it anyway there is a type called "silver seal" or "solder seal". It comes in a tube, is very fine granular, almost a powder, and works pretty well. I've had fewer issues with that stuff than other types. I'd still recommend having it properly tested.