There is nothing in a radiator that can rust. They are either made out of copper and brass soldered together or they are made out of aluminum with plastic headers and are crimped together. The only part this could be contributing the rust would be the head and the block. Given the age of your jeep I would guess itÆs a soldered brass/ copper radiator, and shouldnÆt be a problem, if its an aluminum / plastic one, I would suggest getting one that was soldered together because over time those o-rings between the headers and core will fail. I replaced the radiator in my Æ99 XJ at around 120K miles because the seals were leaking, I was able to find a replacement soldered copper/ brass radiator, and its been working great. Are you sure the leak is coming form the radiator?

Sean