I have an O4 with a 5.4 and 50k miles. Next month, I am driving 200 miles each way (400 miles total) with a 3500lb load (horse and horse trailer).

My truck is ready to go but the radiator hoses are original. They look fine but I am wondering if I should replace them because they're 8 years old.

When does one replace their radiator hoses? When they leak?

 

If you replace them when they leak, it's too late. I would replace them now. Take a feel of them. If they're really pliable, they're reaching the end.

 

When they get soft, or when they get hard. Or when you decide to before they blow out and burn you. LOL