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  • Writer's pictureRALPH COPE

Swap It Like a Pro: A Step-by-Step Guide to Changing Your Excavator's Hydraulic Pump




If the engine of an excavator is akin to the heart, then the hydraulic pump would best be compared to the lungs. Just as the lungs provide oxygen to the heart to distribute throughout the body, the hydraulic pump supplies hydraulic fluid under pressure to various components of the excavator, enabling movement and functionality much like oxygen allows muscles and organs to function in the body.


The hydraulic pump in an excavator plays a critical role in its operation by converting mechanical power from the engine into hydraulic energy. This conversion is accomplished through the movement of hydraulic fluid within the system. Here are the key functions of the hydraulic pump:


  1. Fluid Transmission: The hydraulic pump moves hydraulic fluid from the reservoir to other parts of the hydraulic system. This fluid acts as a medium to transmit power.

  2. Pressure Creation: As it moves the fluid, the pump also pressurizes it. This pressure is essential for the operation of hydraulic actuators (like cylinders and motors) that perform the excavator’s work functions such as lifting, digging, and rotating.

  3. Power Conversion: The pump effectively converts the rotational mechanical power from the engine into hydraulic energy. This involves changing the energy from one form to another, ensuring efficient power transmission.

  4. Control and Regulation: In many systems, the hydraulic pump also helps in regulating the amount of fluid that flows through the system, ensuring that the right amount of power is delivered to various parts of the excavator as needed. Variable displacement pumps, for example, can adjust the flow of fluid depending on the load and the specific task being performed.

  5. Heat Generation and Management: During the conversion and transmission of hydraulic power, heat is generated within the fluid. The pump contributes to managing this heat through the circulation of the fluid, helping to maintain optimal temperature levels within the hydraulic system.


Overall, the hydraulic pump is crucial for the functionality and efficiency of an excavator, ensuring that it can perform heavy tasks effectively by providing a reliable source of hydraulic power.


Components that make up the hydraulic pump?

Hydraulic pumps in excavators are sophisticated components designed to handle heavy loads and rigorous tasks. They come in different types, such as gear pumps, piston pumps, and vane pumps, each having a specific set of components suited to their design. Here are the general components found in most hydraulic pumps:

Casing: This is the outer shell of the hydraulic pump that houses all the internal components. It protects the internal parts from external elements and contains the hydraulic fluid.


Drive Shaft: The drive shaft is connected to the engine or motor and transfers mechanical power to the pump. It initiates the motion needed to pump the hydraulic fluid.


Pump Gears or Pistons:

Each type of pump will have variations on these components based on its specific mechanism, but these are the basics that comprise most hydraulic pumps used in heavy machinery like excavators.


In an excavator, the hydraulic pump is typically located close to the engine, as it needs to be driven by the engine's power. This arrangement allows for efficient transfer of mechanical energy from the engine to the hydraulic pump. Here’s how it is typically positioned:


Near the Engine: The hydraulic pump is usually mounted directly to the engine or very close to it. This proximity allows the pump to be driven by the engine’s crankshaft or a dedicated drive shaft. In some designs, the pump may be directly attached to the engine block.


Central Position: The placement is generally central in the machine's layout to facilitate short routes for hydraulic lines to various components. This central positioning helps in maintaining balanced hydraulic pressure across the system and reduces the risk of leaks or drops in pressure.


Accessible for Maintenance: Despite being close to the engine, the pump is usually positioned in a way that allows easy access for maintenance and repairs. This is crucial because the hydraulic pump is a critical component, and regular checks are necessary to ensure optimal performance.

The specific layout can vary depending on the excavator's design and size, but these general guidelines describe the typical placement of a hydraulic pump in an excavator.


Signs Your Pump May be Failing


Recognizing the signs of a faltering hydraulic pump in an excavator is crucial for maintaining its operational efficiency and preventing potential damage. Here are key indicators that the hydraulic pump may be experiencing issues:


Reduced Hydraulic Power: If the excavator seems less powerful or slower than usual in performing tasks like lifting or digging, it could indicate that the hydraulic pump isn't generating enough pressure.


Abnormal Noises: Unusual sounds such as whining, grinding, or screeching from the pump area often suggest internal wear or damage, such as compromised bearings or misaligned gears.


Hydraulic Fluid Leaks: Leaks around the pump or any part of the hydraulic system can lead to a drop in fluid levels, reducing the system's pressure and efficiency.


Increased Heat Production: Excessive heat from the hydraulic system can be a sign of inefficiency in the pump, possibly due to internal friction, clogged filters, or degraded hydraulic fluid.


Erratic Operation: If the hydraulic functions of the excavator become inconsistent, such as jerky movements or fluctuating tool performance, it might indicate issues with the pump’s flow capabilities.


Cavitation: This occurs when air gets into the hydraulic fluid, leading to vapor bubble formation, which can cause system damage. Symptoms include reduced fluid flow and a 'milky' appearance in the hydraulic oil.


Higher Energy Consumption: If the engine is working harder than usual to perform standard tasks, it could be compensating for a failing pump.


Monitoring these signs can help identify issues with the hydraulic pump early, allowing for timely repairs or adjustments, thus avoiding more serious damage to the excavator.


Frequently Asked Questions


Question: Would having the oil of the excavator tested in a laboratory help in detecting problems with the pump?


Answer: Yes, having the hydraulic oil of an excavator tested in a laboratory can be very beneficial in detecting problems with the hydraulic pump and other components of the hydraulic system. Regular oil analysis provides insights into the health and performance of the hydraulic system through several key indicators:


  1. Contamination Levels: Lab tests can identify the presence of contaminants such as water, dirt, and other particles. Contaminants can cause damage to the hydraulic pump by inducing wear and tear or causing blockages.

  2. Wear Metals: Analysis can detect the presence of metal particles in the oil, which are often indicative of internal wear within the hydraulic pump or other moving components. This can be a precursor to more severe mechanical issues.

  3. Oil Condition: The chemical analysis of the oil can reveal its condition, whether it is degrading, oxidizing, or has lost its viscosity. Poor oil condition can reduce its effectiveness as a lubricant and as a medium for transmitting power, stressing the hydraulic pump.

  4. Additive Depletion: Hydraulic oil contains various additives that enhance its properties. Lab tests can determine if these additives have been depleted beyond acceptable levels, which can compromise the protection and performance of the hydraulic system.

  5. Acidity and Viscosity Levels: Measuring changes in acidity and viscosity can indicate chemical breakdown or contamination of the oil, which can adversely affect the pump and the entire hydraulic system.

Regular oil analysis not only helps in detecting existing problems but also serves as a preventative measure, allowing you to address issues before they lead to significant damage or failure. This practice contributes significantly to extending the life of the excavator's hydraulic components and optimizing its operational efficiency.


Question: How does the hydraulic pump interact with the valve bank?


Answer: The hydraulic pump and the valve bank in an excavator are critical components of the hydraulic system, interacting closely to control and direct the flow of hydraulic fluid to execute various functions. Here's how these components work together:


Pressure Supply from Pump: The hydraulic pump is responsible for providing a continuous supply of pressurized hydraulic fluid. It generates the necessary pressure that drives the system.


Flow Direction through Valve Bank: The valve bank, also known as the control valve or hydraulic manifold, receives this pressurized fluid. It consists of multiple spool valves that control the direction of the hydraulic fluid flow. Each spool in the valve bank can be independently controlled.


Control of Hydraulic Actuators: Depending on the operator's inputs (via control levers or joysticks), the spool valves within the valve bank open, close, or partially obstruct flow paths. This regulates the amount of hydraulic fluid and its direction to different hydraulic actuators, like cylinders and hydraulic motors, which then perform specific tasks such as lifting, digging, or rotating.


Flow Regulation: Besides merely directing the flow, the valve bank can adjust the flow rate to the actuators. This is crucial for controlling the speed of the hydraulic functions. For instance, a slower flow rate might be used for precise positioning tasks, while a faster rate could be required for lifting heavy loads.


Pressure Relief and Safety: The valve bank often includes safety features such as pressure relief valves to prevent over-pressurization, which can damage the hydraulic system. These valves ensure that the system operates within safe pressure limits.


Feedback Loop: In some advanced systems, sensors may provide feedback to the hydraulic pump and valve bank to optimize performance. For example, if a particular function requires less pressure, the pump can adjust its output or the valve can modulate the flow more precisely.


The interaction between the hydraulic pump and the valve bank is central to the functioning of an excavator's hydraulic system. It ensures that hydraulic power is effectively converted into mechanical motion and force, allowing the excavator to perform various tasks efficiently and safely.


Question: If your pump fails, you can either try to fix it or have it replaced. How do you decide what to do in this case?


Answer: Deciding whether to repair or replace a hydraulic pump on an excavator involves considering several factors to ensure cost-effectiveness and operational efficiency. Here’s a structured approach to making this decision:


Assess the Extent of Damage:

Conduct a thorough inspection or have a professional diagnose the issue with the pump. Understanding whether the damage is minor, such as a seal leak, or major, like severe internal wear or catastrophic failure, is crucial.


Consider the Age and Condition of the Pump:

If the pump is relatively new and the rest of the system is in good condition, repairing might be more economical. Older pumps or those that have undergone multiple repairs might be better candidates for replacement to avoid recurring issues and downtime


Analyze the Cost Implications:

Evaluate the cost of repairs, including parts and labor, against the cost of purchasing a new pump. Also, consider potential future repairs if you choose to fix the current pump. Factor in the downtime associated with both repairing and replacing the pump. Longer downtime can lead to greater operational losses, which might justify the higher initial cost of replacement.


Check Warranty and Support Options:

If the pump is still under warranty, repair might be covered, which can significantly reduce costs. Also, check if the manufacturer offers support for repairs or if they recommend replacement.


Evaluate the Impact on System Efficiency:

A new pump may offer improvements in efficiency, reliability, and may even come with updated features that enhance the excavator's performance. A repaired pump might not perform at its original efficiency, leading to increased fuel consumption or reduced operational capacity.


Environmental Considerations:

Consider the environmental impact of both options. A new pump might be more environmentally friendly with better energy efficiency or lower emissions.


Seek Professional Advice:

Consulting with a hydraulic systems expert or the excavator manufacturer can provide insights based on your specific model and operational needs.


Review Historical Data:

If you’ve faced similar issues in the past, reviewing what was done then and how effective it was can guide your decision. Ultimately, the decision to repair or replace a hydraulic pump should be based on a balance of cost-effectiveness, potential downtime, operational efficiency, and long-term reliability. This approach ensures that you maintain the operational integrity of your excavator while managing costs effectively.


10 reasons why you should consider replacing their pump with a used pump from Vikfin.


Choosing to replace an excavator's hydraulic pump with a used pump from Vikfin can offer numerous benefits. Here are 10 compelling reasons for readers to consider this option:


  1. Cost Efficiency: Vikfin's used pumps are significantly more affordable than new ones, providing substantial savings without compromising on quality.

  2. High-Quality Standards: Vikfin ensures that all used pumps meet high-quality standards, having been thoroughly inspected and tested to function like new.

  3. OEM Compatibility: As a provider of OEM parts, Vikfin guarantees that the used pumps are compatible with specific excavator models, ensuring a perfect fit and optimal performance.

  4. Reduced Environmental Impact: Opting for used parts helps reduce waste and the environmental impact associated with manufacturing new components.

  5. Immediate Availability: Vikfin typically has a wide range of used pumps available for immediate delivery, reducing downtime compared to ordering new parts that may have longer lead times.

  6. Proven Performance: Used pumps from Vikfin have proven their reliability and performance in real-world conditions, offering a trusted solution without the uncertainties of new, untested parts.

  7. Warranty and Support: Vikfin offers warranties and support for their used parts, providing peace of mind and protection for your investment.

  8. Extensive Selection: With a broad inventory covering all major OEMs, Vikfin can provide specific parts for a wide range of excavator models and makes.

  9. Expertise and Guidance: Vikfin’s expertise in excavator parts means they can offer valuable advice and recommendations, ensuring that you choose the right pump for your needs.

  10. Enhanced Resale Value: By maintaining your excavator with OEM parts, even if they are used, you can help retain its resale value compared to using non-OEM or aftermarket alternatives.

Choosing a used pump from Vikfin can be a smart decision that balances cost, quality, and environmental responsibility, making it an excellent option for many excavator owners.


A brief guide on how to change the hydraulic pump on an excavator


Here’s a brief guide on safely changing the hydraulic pump on an excavator, focusing on safety protocols, necessary tools, and personal protective equipment (PPE):

Safety Protocols:

Disable Power:

Ensure the excavator is turned off and the key is removed. Lock out the start controls to prevent accidental starting.


Relieve Hydraulic Pressure:

Before starting, operate the control levers to release any residual hydraulic pressure in the lines and pump.


Secure the Machine:

Park the excavator on a stable, flat surface and apply the parking brake. Use wheel chocks for added stability.


Tools and Equipment:

  • Set of wrenches and sockets

  • Screwdrivers

  • Pliers

  • Hammer

  • Hydraulic jack (if needed to support the pump)

  • Oil drain pan

  • Funnel and containers for hydraulic fluid

  • Replacement hydraulic pump

  • New hydraulic hoses and fittings (if needed)

  • Gasket sealing compound


Personal Protective Equipment (PPE):

  • Safety glasses or goggles

  • Gloves (heavy-duty if handling sharp or heavy components)

  • Steel-toed boots

  • Ear protection (if working in a noisy environment)

  • Overalls or protective clothing


Steps to Change the Hydraulic Pump:

Prepare the Work Area:

Clean the area around the pump to prevent dirt from entering the hydraulic system. Have all tools and replacement parts within reach.


Drain Hydraulic Fluid:

Place an oil drain pan under the hydraulic pump. Remove the drain plug and allow all hydraulic fluid to drain completely.


Disconnect Hydraulic Lines:

Use wrenches to disconnect the hydraulic hoses from the pump. Cap the hoses and pump fittings to prevent contamination.


Remove the Hydraulic Pump:

Unscrew the bolts or fasteners holding the pump in place. Carefully lift the pump out of its mount, possibly with the aid of a hydraulic jack if the pump is heavy.


Install the New Pump:

Place the new pump into position. Apply gasket sealing compound if necessary. Secure the pump with its bolts and fasteners, ensuring it is snug and properly aligned.


Reconnect Hydraulic Lines:

Reattach the hydraulic hoses to the new pump. Ensure all fittings are tight and secure to prevent leaks.


Refill Hydraulic Fluid:

Use a funnel to refill the hydraulic system with the recommended type of fluid. Check the fluid level according to the manufacturer’s specifications.


Bleed the System:

Start the excavator and operate the hydraulic controls to purge air from the system. Check for leaks and proper operation.


Test the Installation:

Test the excavator’s hydraulic functions to ensure the new pump is functioning correctly. Observe any abnormal noises or behaviors.


Cleanup:

Dispose of used hydraulic fluid and any contaminated materials in accordance with local environmental regulations.


Final Check:

  • Review all steps to ensure everything is tightened, connected, and operating as it should be. Verify that no tools or materials are left in or around the excavator.

By following these steps and adhering to safety protocols, you can safely and effectively change the hydraulic pump on an excavator.


Conclusion:

Changing the hydraulic pump on your excavator is not just about keeping your equipment running smoothly—it's about ensuring safety, efficiency, and reliability in your construction operations. This guide provides you with a systematic approach, from preparing your work area and draining the old hydraulic fluid, to installing the new pump and testing its functionality. Remember, the key to successful maintenance lies in adhering strictly to safety protocols, using the right tools and protective gear, and performing regular checks and balances throughout the process.


Taking the time to understand and apply these steps will not only help you save on costly repairs and downtime but will also extend the lifespan of your machinery. Moreover, by opting for quality used parts like those from Vikfin, you can achieve optimal performance without breaking the bank. Keep your machinery in peak condition and ensure that your projects always stay on track. Stay safe, stay efficient, and keep building greatness with each component you replace!


This blog aims to empower you with the knowledge and confidence to tackle essential maintenance tasks yourself, promoting a culture of self-reliance and proactive care in the heavy equipment community. So, roll up your sleeves and let's get your excavator back in action with a new hydraulic pump!


Workshop Locations

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Telephone/WhatsApp

083 639 1982 (Justin Cope)

071 351 9750 (Ralph Cope)

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