So
Yesterday I was about to head out for a drive in my 72 convertible and I decided to check the rad’s level. I haven’t had any cooling issues but thought I should check anyway. Expecting to see no issues, but it did.
The cap was full of black corrosion crud. This is from a aluminum rad around 5 years old. The age of when I rebuilt the motor. So my question to you guys is. Why is this happening? Is it because the rad is aluminum and the spring on the cap is steel? The spring and spring alone was jammed packed with that black crud
There should not be any corrosion issues if you are using a typical Prestone ethylene glycol mix of anti freeze and water.
I would drain all the stuff that you can. Put vinegar in the cooling system overnight - it might take 3 or 4 gallons. Drain the coolant in the morning and then flush with water.
Finally refill with a correct ratio of anti freeze and water based on the coolest temperature your area will see.
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Is there a curtain antifreeze to use with an aluminum rad or just the regular antifreeze
Make sure you run a ground strap from the aluminum radiator to the body of the car. It will help stop the galvanic action.
“Is there a curtain antifreeze to use with an aluminum rad or just the regular antifreeze”
What Royce said.
Ground strap……. Is that the reason I got this issue?
So when you said to drain then put vinegar in. Do I run the car and if so for how long
No if I said to run the car I would have.
Brass radiators that came with your vehicle do not cause a galvanic action, but aluminum does and is the reason for grounding it. Two dissimilar metals in a solution with heat and movement create a voltage that can corrode aluminum and cast iron and breaks down the coolant anti corrosive additives very quickly. You can also run a radiator cap with an anode that will serve as sacrificial metal instead of your aluminum.
Thank you for the information and not the attitude the other guy has
Where would one get a radiator cap like that?
Just google it…even amazon has it in all pressure ratings
People who don’t know anything will often recommend adding unnecessary ground wires or even installing a sacrificial anode in the radiator. Neither is a good idea nor needed or beneficial in any way. The internet is like that.
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To answer the OP questions:
Mike
Thank you that was informative and interesting
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Royce, not sure why you’re being so negative here. Thought this was a forum for people to come together and exchange ideas and thoughts. If you disagree, fine, but make your case and try to be civil. To say someone knows nothing is over the top. It’s hard enough to keep people interested in old cars, let’s not scare them away from the hobby with unnecessary attitude.
My responses are based on experience. You might view them as “negative” but they are fact based.
If you install a “sacrificial Anode” the anode is made from Magnesium. Magnesium typically will corrode easily. It becomes magnesium oxide (rust from magnesium) and plugs the radiator.
Coolant normally is very conductive and will ground anything it comes in contact with. There is a galvanic number assigned to all substances. Aluminum and cast iron are right next to one another so very compatible. For example my 427 GT-E has its original aluminum intake which is totally compatible with anything made from cast iron so long as a real coolant is used. Ford 289 and 302 and 351 engines have an aluminum water neck - the same is true of them.
So I made my comments based on fact - nothing else matters.
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You are conflating your experience with automotive fact. I too have decades of automotive experience as a field service engineer. I’m not cocky enough to associate the two (automotive fact and experience). I find it interesting that many aftermarket aluminum radiator manufacturers sell and recommend both anodes and radiator grounds. Once you modify a vehicle by replacing a copper/brass with an aluminum radiator all bets are off as far as galvanic action and interaction. Aluminum is the softest metal in the system which is why it’s attacked first. Ever notice the condition of aluminum thermostat housings in our Cougars? Giving the system an anode to eat instead of the radiator is a better idea than just letting it happen. However, I’ve reread the original post and believe it is truly most likely that the coolant is too old and its anti corrosion additives have been depleted since it likely hasn’t been replaced for 5 years. This is just my automotive two cents. I’ve professionally diagnosed vehicles for 35 years for a major us automotive manufacturer. I’m not looking to argue, but other people might just have valid takes that are based on their experience and training.
You are very ignorant if you recommend either.
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I’ll happily be ignorant in your mind, but you have shown yourself as a conceited ass to many. If you all want to take the advice of this guy as the be all, end all of automotive knowledge, good luck. Aftermarket radiator manufacturers must all be idiots too. We’ve overtaken this post with our back and forth. To the poster I apologize and I’m done
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