equipment and get injured. A leak that drips on hot engine parts may start a fire that could result in the loss of the equipment.
Every joint in a hydraulic system is a potential point of leakage. This is why the number of connections in a system must be kept to a minimum. Leaks often arise from hoses that deteriorate and rupture under pressure. Such a leak is usually first noticed when equipment has remained idle for a period of time and hydraulic fluid is found underneath. Figures 3-47 and 3-48 show the proper procedures for repairing hoses with reusable fittings. You can remove a medium- or high-pressure hose from its fittings by unscrewing the nipple from the socket and then the socket from the hose.
Here are some hints that will help reduce hose leakage and maintenance:
Leave a little slack in the hose between connections to allow for swelling when pressure is applied. A taut hose is likely to pull out of its fittings.
Do not loop a hose unless the manufacturer requires it. This causes unnecessary flexing of the hose as pressure changes. Angled fittings should be used instead of loops.
Do not twist a hose; twisting causes the hoses to weaken.
Use clamps or brackets to keep a hose away from moving parts or to prevent chafing when the hose flexes.
Keep hoses away from hot surfaces, such as manifold and exhaust systems. If you are unable to do so, install a heat shield to protect the hose.
Route hoses so there are no sharp bends. This is critical with high-pressure hoses.
Sometimes you can stop leaks at fittings by tightening the hose connections. Tighten them only enough to stop the leakage. If you cannot stop a leak by tightening, secure the equipment and remove the connection. Inspect the threaded and mating parts of the connector. Look for cracks in the flared ends of the tubing. If O rings are used, examine them for cuts or tears. Any damaged or defective items should be replaced.
Figure 3-47. - Replacing low-pressure hose on a reusable fitting.Continue Reading