Replace radiator hoses with radiator when rust is present in coolant?

Question

The radiator on a 20+ year old Jeep XJ recently bust. The fluid that came out was a rust colour, likely indicating that the radiator was at least partially filled with water instead of coolant (looking at what came out, perhaps entirely filled with water). It's likely been running with that fluid for at least a decade.

The radiator hoses look fine on the outside, but likely have rust on the inside. But, undoubtedly, so does the engine.

When replacing the radiator, do the hoses also need to be replaced because of the rust? Or since the engine already has some rust inside, will it really make no difference?

The engine runs great and has 125K miles.

Answer 1

More than likely the rust came from the engine block, not the radiator. I'm sure it was due to a lack of (or weak) antifreeze as coolant. I think you're on the right track as far as that matters. Radiators are made of either aluminum (usually) or brass (older vehicles ... ie: 50+ years old, so not yours). Neither of these "rust", per se.

As for replacing the hoses, you may want to do it as a maintenance item, but realistically, the rust in the coolant should have little to no effect on them. If the hoses are still pliable and flexible, with no signs of cracking when you flex them, they should be usable without worry. If you think you're going to worry about it, just replace them. You won't be wrong in doing so.