Brass Radiator and Aluminum Block Electrolysis

[luder]

Hello all,

A few years ago I bought a radiator replacement that happens to be made of brass, but my car has an aluminium block. I assumed “all-metal” meant aluminum, but it’s just a marketing babble for a painted brass radiator. Not only is it more expensive and heavier, but I couldn’t return it with an outrageous restocking fee, and decided to go with it.

Since the block is aluminum and the radiator is brass, is there a high risk of electrolysis and the radiator eventually dissolving and leaking? Do you happen to have an aluminum block and brass radiator? What’s your experience?

What would be the right type of antifreeze for this combination? I decided on the violet color Toyota type antifreeze for now, and it hasn’t leaked yet (fingers crossed).

Thank you!

Edit: Some googling tells me it’s the aluminum engine that will dissolve and deposit on the copper/brass radiator with galvanic corrosion if the radiator happens to be grounded. I hope my radiator is not grounded, but how do I test this? As I understand it, if I test with a volt meter from the coolant to the ground, I could be seeing the electrolysis voltage that only happens when I test? Is there a reliable test for this?

Some discussion of this complex topic here for example: http://www.rubiconownersforum.com/forums/25-rubicon-tips-techniques-write-ups/97666-ground-your-radiator.html

Thanks.

Topic

[college man]

Usually you get the electrolysis when two dissimilar metals touch. I don’t believe
you will have any issues.

[luder]

In the case of the brass radiator and aluminum engine, they touch through antifreeze, which in this case is an electrolyte in a cell battery of sorts because of dissimilar metals. Antifreeze is still conductive a little despite water being distilled due to some minerals, etc. If the radiator happens to be grounded (as I understand it – from the factory it must not be grounded at all costs, but I could have screwed up installation). I just need to find a way to reliably test if I inadvertently grounded it and completed the circuit for the electrolysis to occur.

Thanks again.

[college man]

[quote=”01prelude” post=175871]In the case of the brass radiator and aluminum engine, they touch through antifreeze, which in this case is an electrolyte in a cell battery of sorts because of dissimilar metals. Antifreeze is still conductive a little despite water being distilled due to some minerals, etc. If the radiator happens to be grounded (as I understand it – from the factory it must not be grounded at all costs, but I could have screwed up installation). I just need to find a way to reliably test if I inadvertently grounded it and completed the circuit for the electrolysis to occur.

Thanks again.[/quote]

I give it 15+ years to happen. Lets talk then. 🙂

[Shaun Flichel]

[quote=”college man” post=175892][quote=”01prelude” post=175871]In the case of the brass radiator and aluminum engine, they touch through antifreeze, which in this case is an electrolyte in a cell battery of sorts because of dissimilar metals. Antifreeze is still conductive a little despite water being distilled due to some minerals, etc. If the radiator happens to be grounded (as I understand it – from the factory it must not be grounded at all costs, but I could have screwed up installation). I just need to find a way to reliably test if I inadvertently grounded it and completed the circuit for the electrolysis to occur.

Thanks again.[/quote]

I give it 15+ years to happen. Lets talk then. :)[/quote]

+1. It will outlast the vehicle.

[luder]

15+ more years on my engine?? More worried about the brass radiator corroding the aluminum engine. Although, nowadays brass is mostly made of zinc, and zinc is a sacrificial anode…

[Shaun Flichel]

Then find a different rad and live worry free.

[Ty]

Here is some good info on aluminum vs copper/brass radiators.

I personally don’t think you will have problems with electrolysis but more with corrosion of the radiator down the road.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjFo8W9-pvPAhULaz4KHYbnCzEQFggjMAA&url=http%3A%2F%2Fwww.cgj.com%2F2013%2F07%2F16%2Faluminum-vs-copper-brass-radiator-final-thoughts%2F&usg=AFQjCNEuEObpZcw_HAxo-aZJG2NYdt_q6g

[Mike]

If the factory rad was aluminum, you should really replace it with another aluminum unit.

However, if you’re totally committed to using the brass rad, I would suggest replacing your anti freeze often, like every two years. It’ll ensure that the corrosion inhibitors are always up to strength. Also, use only distilled water when mixing your coolant.

[luder]

Thanks for the suggestions. I’ve measured the voltage between the antifreeze and the engine block, and it’s there, but very low. And as long as the radiator is not grounded and the current is not flowing as in a battery, there should be no galvanic corrosion.

[luder]

Of course the radiator is grounded :(. Not sure if they’re supposed to be grounded or not from the factory. I might replace the coolant with the so called lifelong waterless coolant to prevent the engine from corroding. It would suck to have to buy a new aluminum radiator just to prevent corrosion.

[Author]

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