We own a lot of equipment with hydraulic hoses. Most is newer but some is approaching 40 years old and still has many original hoses. Hydraulic hoses failing is a common occurrence for us but the likelyhood of a hydraulic hose failure is every bit as great on the new equipment as the old. One machine in particular is 4 years old and has had 6 different hoses fail on it already. We don't, as a rule, try to guess when a hose is going to fail. However, if two hoses are routed together we will replace both when one fails.