Hydraulic hoses are literally the lifelines of most construction equipment. Nothing can grind productivity to a halt faster than a ruptured hose. A little time invested up front to monitor the condition of the hydraulic hoses and fittings can dramatically reduce expensive failures in the field. The potential cost of hose failure in terms of lost production, environmental impacts and possible injury to operators and others argues strongly in favor of replacing hoses on a time-based schedule, a periodic visual inspection, or some combination of the two. Hose replacement while equipment is already ‘out of service’ as part of a planned preventative maintenance schedule can prevent critical downtime and expense.  Hoses should be replaced as part of a preventative maintenance (PM) program, especially in critical applications. Hose self life is similar to automobile tires. After four to six years the rubber begins to break down and you can expect to see visual cracking and weeping around the couplings.  Begin with a through inspection. If there are no signs of leaking, abrasion wear, cracks or twisting, then there is no reason to proactively replace the hose assembly. Howev...