GROMMET 3466393 - Caterpillar

A. Sight
1. One good way to forestall problems with a hydraulic system is to periodically look over your equipment. Watch for any signs of leakage - a wet machine or hose, oil stains, low levels in the reservoir. It's a good idea to look at the reservoir regularly, not just to check the fluid level but to actually examine the fluid. If the oil in the reservoir has a milky appearance it is probably saturated with air or water. In either case, your hydraulic system is in for trouble.2. Observe the action of the hydraulic cylinders. If the movement is jerky or erratic something is wrong. It may be air in the system or a bent cylinder rod.3. Most important of all, make sure there is sufficient oil in the hydraulic reservoir after the complete system is charged and the cylinders are extended. Follow the manufacturer's recommendations on the fluid level as well as on the type of fluid to use.B. Touch
1. When you put your hand on a hydraulic pump used on mobil equipment and wish you hadn't because it's hot, the pump is trying to tell you something. When the maximum temperature of a hydraulic system exceeds 210°F several malfunctions occur. Oxidation is accelerated. Tests have shown that below 190°F, oil oxidizes very slowly. The rate of oxidation approximately doubles for every 18°F increase in temperature. It is estimated that the working life of most oil is decreased by 50% for every 15°F rise in temperature above 200°F. Oxidation causes sludge to form, reduces clearances, causes corrosion and creates more heat thus establishing a vicious cycle.2. Just because the hydraulic reservoir is not hot does not mean there is no heat problem. A good trouble shooter will feel the fluid conductors in various parts of the system to make sure there are no "hot spots". If any part of a hydraulic system is unusually hot you can be sure there is a problem developing.3. Remember high heat can be very dangerous to a fluid power system and should not be tolerated.E. Smell
1. When hydraulic oil is saturated with air, or when a hydraulic pump is cavitating, the air bubbles in the system go from a sub-pressure condition (vacuum) to a high pressure condition in a fraction of a second which generates a great deal of heat. In fact it has been estimated that a pocket of air in a hydraulic system may reach temperatures in excess of 2000°F. This is hot enough to scorch surrounding oil and a good trouble shooter can smell this "burned" oil in the reservoir. 2. When any of these abnormal conditions are present, a good trouble shooter will follow up. Any factor known to him that could cause the irregularity must be checked out. Nothing should be overlooked. He should obtain a drawing of the system and a specification sheet from the manufacturer so that he knows the system. Although he may have to use pressure gauges, surface pyrometers, flow gauges,