- How to Adjust the Pump Pressure on a Log Splitter
- When and How to Adjust a Load-sensing Hydraulic Pump
- How to Adjust a 2-Stage Pump
- Cat 312, Adjusting Hydraulic Pump Pressure?
- When and How to Adjust a Load-sensing Hydraulic Pump
How to Adjust the Pump Pressure on a Log SplitterForum Rules. Home Forums Reviews Articles Store. Homepage Today's Posts Search. Forgot your Password? Sign Up. Remember Me? Results 1 to 6 of 6. Thread Tools Show Printable Version. How to adjust hydraulic pressure? That seems kind of low. Anyone know what the recommended pressure is and how to adjust the pressure? Re: How to adjust hydraulic pressure? I can't help on the adjustment, but if it's under warranty I'd be calling the dealer. KennyD www. To raise hyd system pressure one needs to turn pressure relief valve on frt end loader valve in until psi is reached. IMHO as long as system pressure doesn't exceed psi then warranty if avaialable shouldn't be affected. I believe the L adjustment would be the same as the older L and L series tractors. There is a plug that you remove down by the hydraulic filter on the bottom. This plug will have a spring under it. You increase the pressure by adding shims between the plug and spring, I think most use a 10 machine screw washer. I'll see if I can find the thread, there was a pretty lengthy one that discussed it. An important trick though, put a shop vac in the fill port for hydraulic fluid. It will draw a vacuum on the case and you will only loose a drop or two of fluid doing the modification. Replies: 8 Last Post:PM. Replies: 2 Last Post:AM. Replies: 11 Last Post:PM. Old well. By megotatractor in forum Rural Living.
When and How to Adjust a Load-sensing Hydraulic Pump
In order for the hydraulic system to run as efficiently as possible, two critical settings are the pump compensator and the system relief valve. Of all of the adjustments that we find made incorrectly, these two are the most common. Often the pressure setting of the pump compensator has been increased, sometimes above the setting of the relief valve. When this happens, the system will overheat badly. We have sometimes even seen heat exchangers added to a system for no other reason than because, at some point, someone turned the compensator above the relief valve. In order to set them properly, they must be set together. The first step is to determine the best pressure at which to set the valves. If we are fortunate, we have designer specifications available. Whenever we do have designer specifications and no modifications have been made to the machine that would change the requirements, we should adhere to the specs. Otherwise we must determine the pressure required to move the heaviest load the machine will ever be required to move. We do this by placing the machine under its greatest load and increasing the pressure until the load moves. When doing this, we must open any system flow controls and isolate any accumulators. Flow controls and accumulators can add resistance to the machine which will affect pressure readings. This is to ensure that the relief valve is set above its cracking pressure to avoid dumping across it, wasting energy and generating heat while moving heavy loads. With the system shut down, isolate the power supply so that the only flow path for fluid from the pump is through the system relief valve. Most well-designed systems have a manual hand valve immediately downstream of the power supply for just this purpose. Turn the relief valve adjustment counterclockwise to a very low setting. Do not turn it past the point where you no longer feel spring tension — many of them will back all of the way out! Turn the compensator fully clockwise. This will make the pump behave as a fixed displacement pump, delivering maximum flow at all times so that the pump will not de-stroke while you are setting the relief valve. Power up the system and you should have oil dumping across the relief valve at a very low pressure. For this example, increase the relief valve setting to PSI. Once the relief valve is set, reduce the compensator setting to PSI and your pressures are set. On a very few machines, the — PSI spread between the relief valve and the compensator settings will not be enough to overcome the cracking pressure of the relief valve. If, once the settings are made you find that the relief valve is getting hot, the relief valve setting must be increased until fluid no longer dumps across it. The most effective way to do this is to install a flow meter in the relief valve tank line and increase the setting until the flow meter reads 0 GPM. If you have no flow meter or if the relief valve tank line is not exposed, a laser temperature gun or an infrared camera can be used to determine if the relief valve is dumping. Call Us Today gpm gpmhydraulic. Search for:. Why do I Need One?
How to Adjust a 2-Stage Pump
If you are operating a vane or gear pump, in most cases the controls are fairly simple. The pump is either loaded doing work or unloaded all flow going back to the reservoir. These are primarily fixed displacement devices so the amount of the flow is only based on the input RPM, otherwise, the flow remains constant. After doing the work, the flow is open back to the tank. Closed circuit pumps offer additional, but different, control options. The amount of flow that each pump can provide is dependent on a rotating group of pistons. By varying the stroke of the pistons, we adjust the displacement of the pump. In a variable displacement pump, we vary the angle of the rotating group, which is done by tilting the swash plate. The swash plate of the pump is operated with a heavy spring and a piston. When the prime mover, electric motor, or another device, turns the pump shaft, the pump will produce maximum flow. The system pressure flows against one side of an internal piston, which is being held by the heavy spring. When the force of the system pressure is high enough to move the piston and overcome the spring pressure, the swash plate angle is changed and the pump flow is reduced. The pump will maintain the set pressure, producing very little or no flow, until the load varies, at which point the swash plate angle changes and allows the pump to produce flow again. This is a very simple control method and, in certain applications, this is all you need. Remember, the flow of the pump is not adjusted until you have built pressure at full displacement. You must have enough HP to take the pump to full pressure at full flow. If there is not enough HP, the prime mover will slow down or stall before the pressure begins to compensate and lower the flow. Application example: you are using a hydraulic motor to operate a conveyor. The load is constant and the motor requires about PSI to handle the load. You set the piston pump compensator at PSI and let it run. Your system will also need a safety relief in case of emergency. System pressure is adjusted using the pump compensator and the system relief should be set a few hundred PSI higher than the pump compensator. Another option is to utilize a load sense compensator. With a load sense compensator, this compensator will include a lighter spring setting to control the swash plate. Upstream pressure is ported into a load sense port on the pump, as the pressure requirement increases, the pressure acts against the load sense piston. Once the pressure requirement is higher than the offset, the pump swash plate angle changes and the pump begins to increase flow, by increasing the swash plate angle, until we have enough pressure to balance the piston. Once balanced, the flow remains steady until the load changes. The offset pressure is normally PSI. With a load sense compensator, the pump produces what the load requires plus the spring offset, normally PSI. With a standard pressure compensator, you would have to set the pump at PSI to accomplish the work. Fifty percent of the time, your system will be operating at PSI of inefficiency, which means heat. With a varying load, the load sense is a much better system. For additional control, you can utilize an electronic proportional flow control or throttle. This would give you full electronic control of the amount of flow the pump produces.
Cat 312, Adjusting Hydraulic Pump Pressure?