Hydraulic power is an efficient method of delivering HP by pumping a fluid through a closed system. If the amount of flow or the pressure unknowingly decreases, the amount of HP delivered to a working unit will be reduced, and a system will not perform as it should.
Testers. Portable hydraulic-circuit testers (Figure 2-20) are lightweight units you can use to check or troubleshoot a hydraulic-powered system on the job or in a maintenance shop. Connect a tester into a system’s circuit to determine its efficiency. Currently, several hydraulic-circuit testers are on the market. Operating procedures may vary on different testers. Therefore, you must follow the operating directions furnished with a tester to check or troubleshoot a circuit accurately.
Improper Operation. When a hydraulic system does not operate properly, the trouble could be one of the following:
• The pump that propels the fluid may be slipping because of a worn or an improperly set spring in the relief valve.
• The fluid may be leaking around the control valves or past the cylinder packing.
Since hydraulic systems are confined, it is difficult to identify which component in a system is not working properly. Measure the flow, pressure, and temperature of a liquid at given points in a system to isolate the malfunctioning unit. If this does not work, take the system apart and check each unit for worn parts or bad packing. This type of inspection can be costly from the standpoint of maintenance time and downtime of the power system.