How Does a 2 Stage Hydraulic Pump Work?

How does a 2 stage hydraulic pump work? Knowing the answer to this question means going back to the basics. This includes understanding that 2 stage pumps are usually called log splitter pumps. In terms of purpose, these pumps are an amazing way to expect better performance without worrying about an increase in the horsepower.

How Does a 2 Stage Hydraulic Pump Work?

A 2 stage pump is often regarded as an excellent time-saver. This is because the pump is composed of two pumping parts, along with an inside pressure-sensing valve which works by cutting between the two. A section of the hydraulic pump creates the max gpm flow rate at a relatively low-pressure rate.

As mentioned, looking inside the housing of this type of pump will introduce you to two components – a huge volume pump, alongside its low volume counterpart.

What makes this pump unique is that it makes possible that a hydraulic system produces either high pressure or high flow, which can easily be powered using an engine of a moderate size. The usual log splitters come between 5 and 12 hp.

In contrast to single stage pump which is composed of a single dual suction impeller that is situated on both vehicle sides and giving volume to all of the vehicle discharges, the 2 stage hydraulic pump features two suction impellers that work side-by-side.

With this in mind, it is the operator’s call whether more volume or more pressure is required. This can be done by choosing the right switch that is located on the panel of the pump.

Working with a Hydraulic Log Splitter

In a standard log splitter, a log is placed by the operator on the splitter, shifting a directional valve so as to route fluid coming from the pump and into the cap end of the cylinder. Then, the smaller pump works by moving the piston rod at a low speed, and can still attain higher pressure in pushing the wedge to the log, splitting it.

Basic components of a hydraulic log splitter (2 stage hydraulic pump):

  • Engine – The engine is typically a small 4-stroke gasoline engine. It works by providing power to the entire system. It is connected to the hydraulic oil pump. A usual log splitter has a 5-hp gasoline engine.
  • Hydraulic Oil Pump – This component produces a continuous high-pressure oil stream, running to a valve. The usual splitter features a 2 stage hydraulic oil pump that is rated at a max of 11 gpm, at 2500 psi.
  • Valve – This part allows the operator to actuate the hydraulic cylinder, thus splitting a log. The valves work by applying forward and backward pressure into the piston. A certain type of valve is called “spool valve” because it looks similar to a spool of thread.
  • Tank – The tank is the component that holds the hydraulic oil which feeds the pump. There is also a filter that keeps the oil clean. It can also be found in the tank. A usual log splitter comes with a 3.5 gallon hydraulic oil tank.

It is also possible to speed up the log splitter. For this, you need to have a bigger hydraulic pump. As you also upgrade your pump, you may also have to upgrade the size of the tank. This will help in preventing fluid overheating. You may also want to increase the size of the hoses, as this will also help in accommodating the increase in the flow rate.

The flow rate of the hydraulic pump can also be adjusted. In every pressure, it is also expected that the pump delivers a particular flow rate.

As such, controlling the flow rate of a pump requires setting the output pressure towards the point using the P-V diagram, allowing the pump to provide the flow rate desired.

How to Adjust a 2 Stage Hydraulic Pump?

2 stage hydraulic pumps are often seen in hydraulic systems. They work by allowing the passage of different substances right into the pump, as well as the other components that are in the system. The different aspects of working can be adjusted, such as the valve accuracy, pressure settings, and creating minor adjustments using tools that you can find at home.

Here are the steps in adjusting a 2 stage hydraulic pump:

  1. Locate the adjustment screw that is situated at the back of the hydraulic gauge. For this process, you can use a flathead screwdriver in turning the screw. This step enables you to easily adjust the needle of the screw. When needed, you can also turn it into zero.
  2. This time, take time in adjusting the pressure switch. This switch can be found at the back of the hydraulic gauge. The best tool for this step is a wrench, using it to loosen the nut on the switch. Turn the adjusting screw afterwards. The pressure switch may also be adjusted in stopping the pump as it reaches a given setting in the pressure. Turn it in a counterclockwise direction to decrease the setting for the pressure switch.

After adjusting the 2 stage hydraulic pump, you can then focus your attention on adjusting the pressure regulating valve. This valve is situated right beside the pressure switch. This can be done with a wrench, loosening the nut on the switch.

Afterward, turn the screw in a clockwise motion to increase the setting for the pressure. Note that the switch needs to be adjusted to make sure that you can achieve a pressure differential of around 300 psi.


How does a 2 stage hydraulic pump work? As mentioned earlier, this equipment is truly a life saver and very effective. It contains two sections for pumping, along with an internal pressure-sensing valve, cutting over between both. A section creates the maximum gallon per minute flow rate at a low pressure. Among the uses include drawing the piston back from a log after splitting the log. Drawing it back to the cylinder requires little force, and should be done fast, so as to expect the best possible flow rate at a lower pressure.