replacing hydraulic pump on log splitter free sample

A: To determine which pump to purchase, you will need to know the following: what HP engine will you be powering my log splitter with, what size reservoir capacity do you have available, what type of pump mount you will be using?

A: There are two common types of mounts used on log-splitters. There is a four-bolt mount and a two-bolt mount. The four-bolt mount pumps generally come in 5gpm-16 gpm sizes and have a ½” keyed shaft about 1-1/2” long. The two-bolt mount pumps come in 22gpm and 28gpm sizes and have a 5/8” keyed shaft that can differ in length.

A: If your log-splitter is moving slow but still capable of splitting the wood it always has, it is most likely stuck in its second stage. In the second stage (or low flow/high-pressure stage) the pump produces 25% or less of its rated GPM but it does it at a higher pressure. The transition from the first stage (or high flow/low-pressure) is an automatic process achieved via internal valving with in the pump. If something within that valving has malfunctioned, and it is typically more economical to just replace the whole pump.

1. If the engine bogs down and stalls out, the pump is likely stuck in its first stage. In the first stage (or high flow/low-pressure stage) the pump produces its rated GPM but it does it at about 400-900psi. The transition from the first stage (or high flow/low-pressure) to the second stage (or low flow/high-pressure stage) is an automatic process achieved via internal valving with in the pump. If something within that valving has malfunctioned, and it is typically more economical to just replace the whole pump.

2. If the engine bogs down slightly but fails to stall out, you most likely have a bad seal on the cylinder piston. It is often more cost effective to rebuild a cylinder than to replace it depending on the extent of any internal damage. Consult with your local hydraulics shop.

A: 2-stage log splitter pumps are sized by how many gallons per minute (GPM) they flow in the low-pressure stage. Most 2-stage Log-splitter pumps will safely create 3000 psi regardless of how quickly they transfer the fluid doing it. So, there is not actually a more “powerful” pump, just slower or faster.

A: The size of splitter is typically specified in tons of splitting force. This number is determined by the surface area of the piston multiplied by the pressure applied by the pump. The amount of tonnage that you will need depends predominately on the type and size of wood that you will be splitting. Hardwoods such as oak and hickory take more force to split than most coniferous soft woods like spruce and fir. The Janka rating is the measurement that they use to rate the hardness of wood. The higher the number, the harder the wood. Log diameter size is another important factor in the amount of force required to split the log. One of the most important factors in determining the Tonnage required to split logs is the moisture content. See below for a decent chart for tonnage requirements for seasoned wood. You will need 50-75% more tonnage for splitting green wood.

A: The tonnage rating on your log-splitter is determined by two distinct factors; piston surface area and pounds of force per square inch (psi) supplied by the pump acting upon that surface. To determine the piston surface area, you must take half of the bore diameter, and multiply that number by itself. Then take that number and multiply by pi (approximately 3.14). This will give you the surface area in square inches. Although your hydraulic pump will be rated to a certain maximum pressure rating, typically 3500psi, most log splitter hydraulic systems have a relief valve limiting the amount of pressure supplied to the cylinder and other components. To find the tonnage of your log-splitter you will take the relief valve setting in pounds per square inch multiplied by the surface area of the piston in square inches, then divide that number by 2000 pounds per ton. See example below for a 4-1/2”cylinder at 3000psi:

A: Your valve will have four ports. The IN port is supplied by the hydraulic line coming directly from the pump. The OUT port will return the flow of oil directly to the reservoir. That leaves the two work ports on the valve. The work port closest to the valve handle will be connected to the barrel port (extending) on the cylinder. Attach the other valve port to the rod port (collapsing) side. See the figure below.

A: Typical Log-splitter valves have three positions. Extend – Center – Retract. The extend position directs flow to where the cylinder expands thus forcing the wedge through the log to be split. The handle must be held in this position to maintain cylinder movement. The valve will spring to center from the extend position when the handle is released. The retract position of a log-splitter valve has a feature commonly referred to as a pressure kick-out detent. Pulling the valve into the retract position detent will cause the cylinder to collapse until it is fully pulled in without holding onto the valve handle. Once the pump pressure builds to a pre-set amount, the internal workings of the valve will force the handle back into the center position automatically.

A: The hoses on your log-splitter should have the rating printed or embossed onto the outside sheathing of the line. If it is not visible or readable it is a distinct indicator of weather damage and or rot, and you should look to have them replaced.

Your log-splitter requires multiple hoses and could potentially have three different pressure ratings (see figure below). The suction line shown in green does not see any pressure, on the contrary they usually have some sort of structure to keep the hose from collapsing. The return lines shown in orange do not typically see much for pressure, but they are typically rated to 350 psi. The actual pressure lines shown in red should be rated to at least 3500psi for your typical log-splitter application.

A: Most Hydraulic systems can be safely operated with either ATF (automatic Transmission Fluid) or a standard petroleum based hydraulic oil. Some Log-splitters have a replaceable filter assembly to help clean the oil clean. If your log-splitter does not have a replaceable filter it would be beneficial to use ATF and allow the detergents in the fluid to help keep things clean.

A: There are many manufacturers of log-splitters out there, and just as many if not more manufacturers of cylinders. The only way to know for sure which cylinder that you have is to contact the log-splitter manufacturer with the model and serial number of your unit and ask for a parts breakdown for their part number for the seal kit.

If this is not an option for you for whatever reason, you can disassemble your cylinder and match up the seals by example with your local hydraulics shop. If you do not have a local shop, or they do not offer this type of service, you will need to measure the hard component dimensions of your cylinder. You will then need to match them with the dimensions of available seals with a seal supplier such as Seal Source, Hercules Sealing Products, or any other national seal supplier. Many of them have an online interface to help you make this selection.

A: There are many manufacturers of log-splitters out there, and just as many if not more manufacturers of cylinders. The only way to know for sure which cylinder that you have is to contact the log-splitter manufacturer with the model and serial number of your unit and ask for a parts breakdown for their part number for the cylinder that they used on that specific unit.

A: The first step in selecting a replacement cylinder for your log-splitter is identifying what style of cylinder that you currently have. While many manufacturers utilize common style cylinders, many do not. Please see the figures below for the most readily available styles.

If your cylinder is held together with four large bolts, you are in luck because this is the most common tie-rod style cylinder. The cylinder will have a clevis mount on the barrel end of the cylinder. The rod end mount is usually threaded to accept a clevis or possibly some other style of end. There are not as many options in this style of cylinder.

If your cylinder has a welded body and has a clevis mount on each end it is a welded-clevis style cylinder. The cylinder will have a clevis mount on the barrel end of the cylinder, with the rod-end mount is usually threaded to accept a clevis or possibly some other style of end.

If your cylinder has a welded body and has a short piece of pipe on each end it is a welded-cross tube style cylinder. The cylinder will have different widths on each end. You will want to place close attention to mounting widths and pin hole sizes to insure compatibility.

If your cylinder has a hole drilled through the rod end of the cylinder, this is what is called a pin-eye style cylinder. These cylinders are commonly available with either a clevis mount or a cross-tube on the barrel end. You will want to place close attention to mounting widths and pin hole sizes to insure compatibility.

If your cylinder is mounted on lugs coming out of the side of the cylinder, this is what they would call a trunnion style cylinder. Trunnion mount cylinders are almost entirely exclusive to the log-splitter manufacturer. You will need to get a replacement from the original manufacturer or contact a machine shop to recreate the mounts on a more common cylinder.

Once you have determined the style of cylinder you are looking for, you will need to determine bore size, the mounting pin to pin length (both collapsed and extended), the rod diameter, and pin hole sizes. Drawings are usually available for individual cylinders to insure a proper fit. It might be necessary to have a local shop alter your log-splitter frame to accept the cylinder, or alter the cylinder to fit your machine.

A: 2-stage log splitter pumps are sized by how many gallons per minute (GPM) they flow in the low-pressure stage. While operating below the bypass setting the pump will transfer that number of gallons per minute.

A: Availability of replacement parts for log-splitter valves depends on the manufacturer of the valve. You will first need to identify the manufacturer of the valve. Northern Hydraulics carries replacement handles and brackets for Cross MFG valves and replacement brackets and detents for the Energy MFG log-splitter valves

A:The retract position of a log-splitter valve has a feature commonly referred to as a pressure kick-out detent. Pulling the valve into the retract position detent will cause the cylinder to collapse until it is fully pulled in without holding onto the valve handle. Once the pump pressure builds to a pre-set amount, the internal passages in the valve will force the spool back into the center position automatically.

If you plan to replace the hydraulic pump in your log splitter or build your log splitter, you should know the size of the hydraulic pump that fits your log splitter. Log splitters are designed to split logs efficiently.

The machine uses a hydraulic system to power the splitting wedge to split logs efficiently. The hydraulic pump is an integral component of gas and electric splitters to provide the necessary power to do the job properly.

A log splitter is a powerful machine that splits logs of various sizes using hydraulic pressure. All log splitters – whether electric, gas, or manual – use hydraulics to feed the splitting wedge to cut the logs to just about any size you prefer.

The hydraulics system found in a log splitter consists of an engine, a hydraulic cylinder, a valve, an oil pump to create oil pressure, and a tank to hold and feed oil through the system.

Since the log splitter pump is one of the most important components of the machine, choosing the right kind of hydraulic pump for your log splitting machine becomes crucial when you need to replace the pump or plan to build your own log splitter.

Hydraulic pumps work according to the theory of hydraulics. The Principle of hydraulics or Pascal’s law governs how hydraulics work. Pascal’s law states that when you apply pressure to a specific point of a closed or confined fluid, the pressure will transmit to all other fluid points without any losses.

The hydraulic pump converts mechanical energy into hydraulic energy by using flowing water. The hydraulic pump uses flowing water to create a hydraulic system.

Even though the system is quite complicated, the operation is simple. Hydraulics provide force in a specific area. This force is what we call pressure which helps the log splitter perform its job effectively.

Log splitter pumps are two-stage hydraulic pumps. The entire splitting system is dependent on the pump. The pump consists of two pumping sections as well as an internal pressure sensing valve. One section of the pump helps generate the maximum flow rate at a lower pressure, and it is used to draw the piston back for the system to reset after splitting the log.

It takes very little force to draw the piston back into the cylinder after splitting the log. But, it should happen quickly. That is why you need the highest possible flow rate at low pressure.

When pushing the piston into the log, you need the highest possible pressure to generate maximum splitting force to split the logs efficiently. The flow rate is not a big issue here. Hence, the pump will switch to a high-pressure and low-volume stage to split the log.

When the size of the pump increases, it requires more fluid. But when there is more fluid in the cylinder of the pump, the speed & force of the pump decrease. That is why you need to choose the right size pump for your log splitter.

You can split logs more efficiently when opting for the correct size hydraulic pump for your log splitter. There are different sizes of hydraulic pumps in the market today. You should do your homework properly and opt for the right size pump for your log splitter.

The latest hydraulic pumps available in the market are based on GPM (Gallons per minute). The higher the GPM, the smaller the cylinder. The splitting force of the pump depends on the cylinder.

The pump that your log splitter needs will be dependent on the engine size of the machine. For example, a 5.5-6 hp engine can handle an 11 GPM 2-stage hydraulic pump, while an 8 hp or bigger engine can handle a 16 GPM 2-stage pump.

The engine of a log splitter works on hydraulics. While the pump will create the driving force, the hydraulic cylinder will work in unison with the valves, influencing splitting power and speed. If your log splitter has a 6-7 Horsepower engine, you should opt for a two-stage hydraulic pump (about 3000 PSI) with 11 GPM.

To get more speed, the pump either needs more flow (GPM) or a smaller cylinder. Smaller cylinders don’t require more power but will produce less force. More flow comes from a larger hydraulic pump. You will get the same force with a larger pump but supply more horsepower to the new hydraulic pump.

Are you planning to replace the hydraulic pump in your log splitter or build your own log splitter? If so, you should understand the basics of how a hydraulic pump works and what size pump to choose for your log splitter. To achieve automation, efficiency, and effectiveness, all log splitters rely on hydraulics.

Therefore, you should not worry too much as the size of the pump is only one aspect to look at. But the right decision about the size of the hydraulic pump is always useful in usage.

2-stage hydraulic pumps are used in motor-driven operations wherein a low-pressure, high rate inlet must be transferred to high pressure, low flow-rate outlet. Single-stage pumps are rated to a static max pressure level and have a limited recycle rate.

To achieve high pressure without a 2-stage unit, the drive engine would require significantly higher horsepower and torque capacity but still lack an effective cycle rate. Other hydraulic pump variants exist – such as piston pumps – but are expensive, making 2-stage units more feasible.

For example, a single gear hydraulic pump might be designed to generate a high-pressure output. Still, it will be unable to repeat a cycle rapidly due to a necessarily low flow rate at the intake. A 2-stage unit ensures consistent flow to increase cycle turnover.

2. Once the first-stage pressure meets a certain pressure threshold, a combiner check valve will open and feed into the second-stage, small-gear unit – joining flows at relatively low pressure.

4. A small amount of fluid may feedback to a load sensing pin to measure the pressure at the outlet and signal lower flow rate in the first unit, lowering the pressure and providing the conditions for a cycle to repeat.

A piston pump operates according to variable displacement. Flow is determined by the angle of an internal slant disk attached to the pump shaft. Pump adjustments – like torque or horsepower limiters – allow piston pumps to emit a max flow rate regardless of pressure level.

In most cases, hydraulic piston pumps are an order of magnitude more expensive than gear-based pumps. Potential downtime and part replacement in high volume work conditions exacerbate price disparities further.

Chiefly: fuel and power consumption. A piston pump operating in high-pressure ranges will regularly demand the full horsepower capabilities of its associated drive engine – increasing the power utilization of the system.

Opportunity cost may also be considered when using a piston pump. Depending on the application (e.g., log splitting), work output can be heavily impacted by the cycle speed of the pump. Not only is a piston pump more expensive to peruse, it is also slower than 2-stage pumps.

Panagon Systems has specialized in manufacturing industry-standard and custom hydraulic assemblies for 25 years. Reach out to our team for a consultation on your specific operational and equipment needs.