Conmpatibilityy of Toyota Red Coolant to Brass and Aluminum? (1 Viewer)

[83bj60]

Hey Folks,

[Note: I'm going to double post this for better exposure, one in the forum, the other in the Diesel Tech and 24 volts Systems forum in the hope of getting more responses.

If the moderators believe one post is better, feel free to remove one or concatenate the two into one and sorry for the inconvenience....]

As you know I own a 1991 HDJ81 with 1HD-T diesel engine.

That engine has an aluminum radiator, and I presume, aluminum heater cores as well.

I have not seen any brass or copper parts in the coolant plumbing so far. I presume the thermostat is brass, however it is a very small amount of brass in the system so I don't think it would have a significant impact on the formulation or galavanic properties of the system on aluminum when using the Toyota Red Coolant.

Of course I could be mistaken.

My question is to those who understand chemistry better than I do, how would installing a brass part in the cooling system affect the coolant or the long term corrosive effects on other parts of the system, especially aluminum parts? I would like to avoid possibly corroding the aluminum rad and heater cores by installing this brass part in the system.

 

[NaterGator]

I'm not sure of the specific materials used to make various components (thermostat, inside the water pump, etc) but if you add brass to aluminum components it will eventually corrode the aluminum. There are various anti-corrosion additives to coolant, but it's not a game I would play if I could avoid it.

I thought people were using 3-core copper radiators, but I may be mistaken

 

[83bj60]

My 1991 HDJ81 has an aluminum rad. I intend to install a brass coolant heater. Surface area is going to be a fraction of that of the aluminum, though, so presumably galvanic effects are going to be minimal. I'm just being fussy about it and would like to know more.

I have been reading about Toyota Red and Toyota Green and chave come to the conclusion the Red (which my truck uses at this time) is probably best, but I'm not sure if introducing more brass will cause long term problems and wanted to find out more.

Essentially, I'm modifying the chemical makeup of the engine's internal part slightly.

 

[NaterGator]

What you'll have is (as you know) galvanic corrosion.

Introducing brass will cause corrosion to start. Your antifreeze/water ratio will contribute to how quickly the corrosion takes place, but even a heavy mix is still electrolytic. Your two primary concerns will be keeping on top of sediment suspended in the coolant caused by the corrosion, and failure of any aluminium in the loop.


Somebody may have practical experience doing this in your application, which would be the best thing.

 

[83bj60]

OK, good point. But what about the thermostat? I guess it would all depend on the extra surface area of the metal of my brass part?

I could also coat the whole thing with tin, would it not mitigate the problem, or would it be worse? isn't tin less reactive than brass?

Hmmm!