Do you need to isolate an aluminum radiator?

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sport74

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A coworker (who is a hot rodder and has built many cool rides and I trust his info) told me that he has cracked tanks on aluminum radiators by bolting them solid to the core support. He suggested using rubber isolators. I'm not opposed to this, as it does eliminate stray current which can corrode aluminum. My main concern is has anyone else ever experienced a cracked tank from not being isolated?
 
An aluminum radiator can turn to mud internally very quickly from electrolysis. If your car is properly grounded, you should not have to also ground the radiator to the support but it wouldn't hurt and wouldn't be that hard to run a couple ground straps from the radiator bolts to the support. There are also products you can put in the cap and in the petcock that prevent electrolysis.
 
come to think of it: I think every newer rad is somewhat of a floater install...anyone confirm? Maybe expansion control? Oof, I just realized mine is bolted straight to the rad support.....
 
come to think of it: I think every newer rad is somewhat of a floater install...anyone confirm? Maybe expansion control? Oof, I just realized mine is bolted straight to the rad support.....
This barracuda is the third car I`ve put an alum. rad. in . I have only made sure to shim the rad. where needed to prevent "any" twisting or lop sided puling up tight. No anodes, no ground straps, no problems.
 
I just installed an aluminum radiator using rubber washers to cushion, also grounded it to the frame.
 
i think grounding your aluminum rad is a no no.You don't want current flowing.
Frame and aluminum are the dissimilar metals and the coolant is the electrolyte.
Most cars had the rad grounded from the factory and that ground should be rem'd.
you can install a sacrificial zinc anode from an outboard.The problem usually occurs
if you use high mineral content water in your cooling system.
..this is just stuff i have read...who knows?
 
I installed my aluminium radiator with rubber so it was not touching any metal but specifically ran a wire to ground it, thought you have to ground it to prevent electrolysi? But have no idea just read that somewhere..
 
...if you ground an aluminum rad you create a battery.
One terminal is the chassis (steel),one terminal is aluminum (the rad) and your coolant is the electrolyte.Griffin use to have a write up on their website recommending you remove the ground
the factory installed on the rad ...if you use an aluminum rad.
 
Agreed, I would worry about fixing the stability of your car / frame rails too if the radiator starts to crack open over time.
 
Mine aluminum radiator is mounted metal-metal and has been for 20 years. Must be okay if it lasted this long! I thought about rubber mounting it - but why?
 
A coworker (who is a hot rodder and has built many cool rides and I trust his info) told me that he has cracked tanks on aluminum radiators by bolting them solid to the core support. He suggested using rubber isolators. I'm not opposed to this, as it does eliminate stray current which can corrode aluminum. My main concern is has anyone else ever experienced a cracked tank from not being isolated?

The main concern about solid mounting in an A body is flexing of the core support, and applies to any radiator actually.
That's why they make the weld on supports for that area, as that flex can separate the surrounding mounting metal from the radiator core. (or crack a tank)
 
For a car that will get lots of miles use some sort of rubber isolation for mounting an aluminum radiator. Aluminum has a short fatigue life so keeping the flex down helps it last.
Demon has crossflow with rubber cradle bottom and top. No mounting flanges.
Aspen wagon has side flanges bolted thru core support with rubber washers to isolate it somewhat.
Dont have to do it but for my money I will.
Not cheap to replace an aluminum radiator.
 
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