we have had the same issue and yes, signs of wear/burns means they should deffinately be changed out. and we had the same OSHA class where they talked about lines being wrapped in what looks like fiberglass cloth to prevent a single hose from being caught on something and being torn off and also to prevent hydraulic oil from spraying a fine mist that could be flammable. after which we turned in a number of trucks to be repaired (have them wrapped) and company pitched a bitch. the same company that insisted we take the class now doesn't want to act on what we learned. if you look new bucket trucks and we have gotten quite a few over the last 3 years or so do come from the factory with all hoses around bucket area wrapped completely toghether. our linemen feel after a bucket goes in for work on hoses they should be wrapped the way they were from the factory. so far we haven't got much satisfaction on this issue. by the way we had a guy from parr give OSHA class, by far the best and most imformative safety class this company has put out in 10 years.