After several hours, a standard pump would likely fail due to the need to maintain constant pressure. The pump is continuously keeping the relief valve open, except when the cylinder is in motion. By adding a check valve and pressure regulator, the pump’s workload is reduced, making the system more efficient, safer, and longer-lasting. A variable volume pump with built-in pressure control can serve the same role as the pressure regulator in this setup. The pressure regulator keeps system pressure between two preset limits and relieves the pump when no components are in motion, directing flow back to the reservoir without restriction. With the regulator valve added, the relief valve acts as a safety valve, preventing system damage if the regulator or pump control fails.
The hydraulic system is practical, but modern equipment typically includes more components to enhance efficiency, safety, and emergency operation.
A complete Automotive Lift Repair Tampa Florida hydraulic system is what you’re looking for. Beyond the previously mentioned components, it features additional check valves, a pressure gauge, filters, and a hand pump. The hand pump serves as an auxiliary system, typically used as an emergency power source if the main power pump fails.
This system can be further expanded by adding a pressure manifold, more control valves, actuating mechanisms, and multiple power-driven pumps in parallel. It’s important to remember that all systems, no matter how complex, can be broken down into simpler components. Even the most intricate system can be understood by analyzing it as a series of simpler systems.
TYPES OF HYDRAULIC SYSTEMS
There are two primary types of hydraulic systems in support equipment: open-center and closed-center systems, or in some cases, a combination of both.
An open-center system allows fluid to flow without generating pressure when the actuating mechanisms are inactive. The fluid moves from the reservoir, through the pump and selector valves, and returns to the reservoir. In this system, pressure is only created when needed, controlled by open-center selector valves, and limited by a system relief valve. The selector valves are connected in series, and pressure only builds when a subsystem is activated by adjusting the selector valve. When the valve is in the neutral position, the open-center valve directs fluid to the return line. When moved out of neutral, the valve builds pressure in the actuating section, operating the chosen mechanism. In an idle state, with no active mechanisms, the pump continues running without pressure buildup, meaning there is no load on the pump. Open-center systems use constant volume pumps and generally do not require pressure regulators.
Closed-Center System
A closed-center system, on the other hand, maintains fluid under pressure as long as the pump is operating. When the pressure reaches a predetermined level, a pressure regulator or the control valve of a variable volume pump relieves the load on the pump.
The previously discussed hydraulic system is a closed-center system, where subsystems can be integrated. Unlike an open-center system, closed-center systems feature selector valves arranged in parallel rather than in series.
HYDRAULIC SYSTEM TROUBLESHOOTING AND MAINTENANCE
Automotive Lift Repair Tampa Florida Hydraulic systems consist of two main sections: the power section and the actuating section. The power section generates, controls, and directs fluid pressure to operate various mechanisms, while the actuating section is responsible for performing the mechanical tasks.
Basic Open-Center Hydraulic System
The actuating mechanisms, including components like brakes, steering, lift cylinders, extend cylinders, and hydraulic motors, rely on the power system. Troubles in the actuating system may sometimes be caused by issues in the power system, and similarly, problems in the power system might be due to leaks or failures in one of the actuating units. When any part of the hydraulic system fails, refer to the schematic diagrams in the relevant technical manual and use equipment tests to trace the problem. It is important to emphasize that no unit should be removed, replaced, or adjusted unless there is a strong reason to believe it is faulty.
Troubleshooting
Most Automotive Lift Repair Tampa Florida hydraulic issues fall into one or more of these categories: insufficient fluid supply, external leaks, internal leaks, defective units, or issues related to mechanical control linkages and electrical circuits.
A lack of fluid in the Automotive Lift Repair Tampa Florida system can result in no pump delivery or slow, erratic performance. The reservoir should always have enough fluid to keep the system fully supplied and prevent the pump from running dry. Always use the correct hydraulic fluid and do not mix fluids or reuse old fluid. Ensure that all new fluid is filtered before adding it to the reservoir. If a unit shows external leakage, repair or replace the defective part.
If foreign particles are found when disassembling a unit, trace the source. A common cause is flexible hose deterioration or improper installation, which can release small slivers of hose lining into the system, leading to leaks or inoperative units.
To troubleshoot Automotive Lift Repair Tampa Florida hydraulic system malfunctions, it is essential to understand the system and its components thoroughly, as well as how the components interact. For example, a good understanding of how a pressure regulator works can help troubleshoot both the regulator and the overall system.
Automotive Lift Repair Tampa Florida Pressure regulators are generally reliable, but they can malfunction. In many cases, the regulator’s performance can reveal other issues in the system, such as hidden leaks. Always begin troubleshooting by checking for obvious issues, like low fluid levels or closed shutoff valves, before focusing on the regulator itself.
Troubleshooting the pressure regulator involves timing its operational cycle, from cut-in to cutout and back again. A typical regulator in a normal system follows this cycle within a specific time frame, which can be found in the equipment manual or estimated by maintenance personnel.
With a constant volume pump, the Automotive Lift Repair Tampa Florida system should pressurize within a predictable time. For instance, if a pump outputs 6 gallons per minute and the system requires 1 gallon to be fully pressurized, it should take about one-sixth of a minute (10 seconds) to pressurize the system. However, if there’s an internal leak, some fluid is lost, and the system won’t reach full pressure within that time, preventing the regulator from cutting out.