Excavator Hydraulic System – The Ultimate FAQ Guide
Hydraulic systems in excavators are important as they help these excavators complete heavy tasks easily. Excavators don’t necessarily work in earthmoving sites – you can use your excavator to lift extremely heavy objects.
Here’s the deal: Your excavator hydraulic system is so important that your excavator cannot work without it. Remember, your excavator works systematically – different components depend on each other for optimal functioning.
You’ll, therefore, need to understand the following concepts about your excavator hydraulic system:
- What an excavator hydraulic system is and how it functions
- How to maintain, diagnose, repair, and/or replace worn components of the excavator hydraulic system
- Where to get the best excavator hydraulic system aftermarket components at a reasonable price
Keep reading this FAQ guide to find out more details on your excavator hydraulic system.
1. What Is A Hydraulic System in An Excavator?
An excavator hydraulic system enables your excavator to perform the most basic functions such as moving, earthmoving works, lifting heavy objects, etc.
Check this out: When your excavator engine runs, it pumps hydraulic fluid to the hydraulic system at high pressure. Your excavator heavily relies on this hydraulic system for it to complete even the most basic tasks.
2. Which Type of Hydraulic System Does An Excavator Use?
Your excavator uses an open-circuit hydraulic system. It also uses a variable displacement hydraulic pump which enables the lift of heavy objects or even complete earthmoving tasks.
3. What Are the Components of A Hydraulic System in An Excavator?
Your excavator hydraulic system has different components that work together to ensure that hydraulic fluid gets pumped to different parts of the excavator. Check out these components that team together to form the excavator’s hydraulic system:
- Hydraulic pump– the hydraulic pump is one of the primary components every hydraulic excavator must have. As its name suggests, the excavator hydraulic pump pumps hydraulic fluid to different excavator parts like the arm, final drives, etc.
- Hydraulic Filters– Your excavator hydraulic system has a filter which is a vital component as well. It sieves contaminants from the hydraulic fluid, therefore, ensuring that other hydraulic system components do not get damaged from contaminants. It works by allowing contaminated hydraulic fluid to pass through it and then it sieves the contaminants. After the sieving process, the hydraulic fluid then exits the filter.
- Control Valves– Hydraulic control valves are used by excavator hydraulic systems to control the amount of pressure passing through it, therefore maintaining the hydraulic pressure. It is important to ensure that your excavator control valve is in proper working condition, as it significantly affects your excavator’s performance.
- Valves and Seals – these components ensure that hydraulic fluid does not go back or even leak as the excavator works.
- Hydraulic fluid– the hydraulic fluid is what the hydraulic system uses to transmit hydraulic pressure to different excavator components. When selecting the ideal hydraulic fluid for your excavator, you’ll need to put some considerations in place as you will shortly find out later on in this guide.
- Hydraulic Reservoir– it acts like a mini-tank that holds the hydraulic fluid. It allows contaminants to settle at its base as well as transferring heat from the hydraulic system. The reservoir also helps release air and moisture from the excavator’s hydraulic system.
Please note that these are the basic components that each excavator must have – different excavators may have additional components.
4. How Does A Hydraulic System Work in An Excavator?
Your excavator hydraulic system works by first receiving hydraulic fluid under high pressure from the excavator’s engine. Then, the main hydraulic pump pumps hydraulic fluid from the excavator’s hydraulic system to the control valve by creating a vacuum at its inlet. Doing so allows atmospheric pressure to push hydraulic fluid from the reservoir into the pump’s inlet.
The control valve then controls the amount of hydraulic fluid that is transmitted to different excavator components, depending on the need. The hydraulic fluid then returns to the hydraulic fluid’s reservoir for pumping again. Solid contaminants from the hydraulic system collect at the bottom of the hydraulic reservoir. The system also has a filter that acts as a purifier. It collects solid contaminants from the hydraulic fluid, therefore ensuring that other excavator hydraulic components do not get damaged.
5. What Is the Optimal Hydraulic Pressure that Should Be Produced By An Excavator Hydraulic System?
Here’s the deal: Different types of excavators have different optimal hydraulic points. Check this out: There are three different types of excavators:
- Mini excavators– they are the smallest type of excavators and they are used to complete light tasks easily and efficiently.
- Standard excavators– they are the most common types of excavators that are mostly used to complete medium-sized tasks. They are significantly bigger and stronger compared to mini excavators.
- Heavy-duty excavators– they are the largest type of excavators manufactured by man. They are widely used to mine raw materials that are found under extremely hard grounds. They are way stronger than standard excavators.
Now, it is hard to clearly state a definite hydraulic optimal pressure for your excavator. It varies depending on the type of excavator you have. It can also go as far as varying depending on the brand of your excavator. Consider checking your excavator’s operations manual to find out the optimal amount of hydraulic pressure your excavator hydraulic system needs to produce. If the pressure does not meet the recommended amount, you’ll need to carry out a complete diagnosis of your hydraulic system, as you will shortly find out later on in this guide.
6. Why Does My Excavator Hydraulic System Leak?
The most probable reason why your excavator hydraulic system may leak at any point is because of a damaged seal. Seals are in charge of ensuring that there are no leakages in your excavator’s hydraulic system.
Apart from seals, consider checking your valves. Damaged valves not only cause leakages at any point of the hydraulic system but also cause low pressure or extremely high pressure in the hydraulic system. KS XuGong offers you the best, high-quality hydraulic seals and valves that guarantee you a longer service life as well as a healthier and stronger excavator. Reach out to us today for the best offers globally. We have so much to offer, as you will find out later on in this guide.
7. How Should I Diagnose A Faulty Excavator Hydraulic System?
Your excavator hydraulic system may experience failure at some point as you use your excavator. You’ll need to properly diagnose it to save time as well as solve the problem you are facing. There are many symptoms of failure that your excavator hydraulic system may portray. Check them out:
- The system is inoperative– you’ll need to check if there is sufficient hydraulic fluid in the hydraulic system. If not, top it up. Also, consider checking for leaks.
- Another reason could be that you used the wrong type of hydraulic fluid. You’ll need to change the oil and replace it with the recommended one.
- The other reason could be that you have a clogged filter that is unusable. Consider replacing the filter. Some mechanics may recommend cleaning it, but that may solve the problem temporarily.
- Your hydraulic lines could also be clogged – you can decide to clean or even replace them if the damage is too extensive.
- Another reason could be air leaks present in the suction line. They can also make your excavator’s hydraulic system inoperative. Consider repairing or replacing the suction line if the damage is extensive.
- Worn out hydraulic pump could also be the cause of your hydraulic system’s inoperative nature. Consider replacing it. Also, check if your excavator’s hydraulic fluid is contaminated. If so, replace it before using your excavator.
- Worn components such as the valves could also make your excavator hydraulic system inoperative. Consider carrying out tests for internal and external leakages, replace damaged components and also check for other underlying causes for premature failure.
- Leakages also render hydraulic systems useless as they cannot generate the optimal amount of pressure necessary for your excavator hydraulic system to run as it should. Consider replacing any worn seals or valves to rectify this issue.
- The load that you are trying to move with your excavator could be too heavy for your excavator. Consider checking your excavator operations manual for the maximum load limit.
- Erratic operation– the first reason why your excavator hydraulic system operates erratically is that it has air in it. Consider checking for leaks on the suction side and repair. Another reason could be that your hydraulic fluid is too cold – you’ll need to allow the hydraulic fluid to warm up before using your excavator.
- Also, check for damaged or dirty/clogged components. If this is the reason why your excavator does not operate optimally, consider cleaning and/or replacing accordingly. Also, check for blockages or restrictions in the hydraulic lines. If the blockages are too extensive, consider replacing these hydraulic lines.
- Slow responses/operation– the first reason why your excavator system could be responding slowly to your commands could be because the oil is too viscous. Your oil could be too viscous because it is too cold. Consider letting your excavator warm up before using it for a more rapid response.
- Your pump could also be another reason why your excavator hydraulic system responds slowly. You can try to increase your excavator’s engine speed to see if the pumps will start pumping faster.
- Worn-out components are also another factor to consider. For example, if your excavator main pump is severely worn, it will force the hydraulic system to respond slowly as it is unable to pump hydraulic fluid optimally.
- Leaks are also a probable reason why your excavator hydraulic system responds slowly. When leaks are present in your excavator hydraulic system, it is unable to build the optimal hydraulic pressure necessary for running the hydraulic system. You can rectify this problem by tightening any loose hydraulic systems components, replacing any worn seals and/or valves as well as using the recommended type of hydraulic fluid.
- Hydraulic fluid overheats– the most common reason why excavator hydraulic systems overheat is that you’ve used the incorrect type of hydraulic oil, there is insufficient oil in the hydraulic system or your hydraulic oil is dirty. Consider replacing the oil as well as the hydraulic filter.
- Another reason could be that your excavator engine is running too fast. Consider reducing the excavator engine’s speed.
- The most probable reason why your excavator hydraulic fluid overheats is that the cooler is no longer in use. Consider replacing your excavator hydraulic fluid cooler with a new aftermarket cooler.
- Internal leakages could also mean that your excavator’s hydraulic system overheats. Consider replacing any worn parts to rectify this issue.
- A malfunctioning hydraulic component could also cause your hydraulic fluid to overheat. Remember, the hydraulic system runs effectively and efficiently when each component’s health is at its best.
- A dirty reservoir could also cause this overheating issue. You can try cleaning the reservoir to rectify this problem.
- Oil Foams– The most common issue is that your excavator hydraulic oil is dirty. It could also mean that you used the wrong type of hydraulic fluid. The next probable cause for this problem is that your excavator hydraulic system has air leaks.
- Noisy Hydraulic Pump– Your excavator hydraulic pump could be noisy because there is insufficient hydraulic oil in your excavator hydraulic system. It could also be noisy because you used the wrong type of hydraulic fluid, or simply because your hydraulic oil is foamy. Consider draining the hydraulic fluid and replacing it with the correct type.
- Check the health status of your excavator hydraulic pump. Repair and replace accordingly if the problem persists – the hydraulic pump could be completely worn out.
- Damaged Shaft Seal– When your hydraulic system has a blown shaft seal, consider checking the pump and the motor. The shaft seal gets damaged if the pump shaft spins in the wrong direction.
- You can also check if the issue lies within the motor if the drain line fails to hook up.
- The only way to rectify the above issue is by replacing the shaft seal. Remember to follow your excavator manufacturer specifications when replacing this shaft.
- The pump and/or motor is leaky– A leaky pump and/or motor suggests that your shaft seal is damaged. You’ll need to replace this shaft seal to rectify this issue. Also, consider checking for any misalignment.
- If the shaft seal is okay and there is no misalignment, consider checking for any breakages within the pump and the motor. You can repair or replace accordingly depending on the degree of damage.
- Your excavator control valve leaks (external)– Consider checking for any loose bolts and tightening them accordingly to rectify this issue. If there are any worn-out seals, consider replacing them as well as they could significantly contribute to this issue.
- External leaks within the control valve could also mean that there is back pressure or some sort of restriction within the hydraulic tank. Consider checking the control valve’s couplers. Also, check if the control valve has any cracked part on its body or on the ports.
8. Why Does My Excavator Have Weak Hydraulic Power?
This is a common issue faced by most operators in the field as they operate their excavators. Now, there are several reasons which could contribute to this issue. Check them out:
- The first reason why your excavator loses hydraulic power is that the hydraulic oil is too viscous. Your oil could be too viscous because it is too cold, or simply because you used the wrong type of oil. Consider letting your hydraulic oil warm up first before proceeding to use your excavator. Also, consider replacing the oil with the correct type.
- Leaks are also a probable reason why your excavator hydraulic system has a weak response. Leaks make your excavator hydraulic system weak, as it is unable to build the optimal pressure required to engage your excavator’s hydraulic components. Consider replacing your excavator hydraulic system’s seals wherever there is leakage, or even tightening loose components.
- If your excavator hydraulic system has any worn-out components, consider replacing them because they could be the reason why your excavator has a weak hydraulic system. Remember, this system’s components rely on each other to work at their optimal levels.
- Your excavator pump is yet another issue that can make your excavator hydraulic system weak. If the pump is running at a low speed, consider increasing your excavator’s engine speed which in turn will engage the hydraulic pump accordingly.
9. Why Does My Excavator Hydraulic System Overheat?
The most common reason why excavator hydraulic systems overheat is that you’ve used the incorrect type of hydraulic oil, there is insufficient oil in the hydraulic system. It could also be that your hydraulic oil is dirty. Consider replacing the oil as well as the hydraulic filter to rectify this issue.
Also, internal leakages could be another major reason why your excavator hydraulic system overheats. You can rectify this issue by replacing any worn-out components. Apart from that, an excavator hydraulic system component could be malfunctioning – it can make your excavator hydraulic system overheat.
The final major reason why your excavator hydraulic system overheats is that the hydraulic cooler is no longer functional. You’ll need to replace it as soon as possible to rectify this issue with a high-quality aftermarket hydraulic cooler from a reputable excavator parts manufacturing company.
10. What Happens When My Excavator Hydraulic System Overheats?
As you’ve read earlier on in this guide, excavator hydraulic systems overheat because of inefficiencies – that is, the hydraulic fluid is not sufficient. This inefficiency means that your excavator hydraulic system is weak. The second thing that happens when your excavator hydraulic system overheats is that the seals get damaged. High temperatures will eventually prematurely damage your excavator hydraulic seals.
The third thing that happens when your excavator hydraulic system overheats is that it starts damaging other hydraulic system components. Remember, there could be a possibility that your excavator hydraulic system components are malfunctioning, for example, the main hydraulic pump. Malfunctioning means that the damaged components are not performing optimally, which can significantly affect the health and subsequently the performance of other excavator hydraulic components.
The fourth thing that happens when your excavator hydraulic system overheats is that hydraulic fluid gets too thin. When the hydraulic fluid gets too thin, it can start leaking externally, which is not a good thing. The seals will be unable to prevent this leakage.
The final major thing that happens when your excavator hydraulic system overheats is that the hydraulic fluid starts degrading. This degradation means that even the best, high-quality hydraulic fluid will get damaged prematurely before the next service reaches.
11. What Is the Optimal Level of Hydraulic Fluid in An Excavator’s Hydraulic System?
Most excavator hydraulic systems have a specified optimal level of hydraulic fluid. You’ll need to check your excavator service manual to find out the optimal level of hydraulic fluid in your specific excavator make and model.
Remember, there are three types of excavators as you read earlier on in this guide. Each excavator type has a different optimal level of hydraulic fluid in its hydraulic system. That’s why it is difficult to clearly state the optimal hydraulic fluid level of all the different types of excavators.
12. How Is the Hydraulic Fluid Level Checked-in An Excavator?
Checking the level of your excavator hydraulic fluid requires you to carry the following steps:
- First, you’ll need to ensure that the excavator is parked on stable and firm ground – in other words, flat grounds are ideal. Lower the excavator’s arm to the ground and then switch off the excavator’s engine.
- Then, proceed to check the hydraulic level gauge – it will show you if your hydraulic oil is at the center of the gauge. You’ll need to put temperature into consideration, as it can affect the measure – it may not necessarily lie at the center.
- If the gauge displays that the excavator’s hydraulic oil lies at the center, then there is enough hydraulic fluid in your excavator. If the gauge fails to lie at the center, consider topping off the difference using clean, high-quality excavator hydraulic fluid. DO NOT start the engine before doing this as it could damage your excavator.
Also, when topping off hydraulic fluid, remember to use identical hydraulic fluid types.
- Top off hydraulic fluid using the recommended specifications as per the manufacturer. You can find these specifications on your excavator’s service manual.
You can find out the recommended amount and type of hydraulic fluid your excavator requires by reaching out to your favorite mechanic. You can also get this information by reaching out to a reputable professional company. KS XuGong has skilled and experienced customer service reps that help you make a solid decision by advising you accordingly, depending on your unique requirements.
13. Why Is My Hydraulic Fluid Too Thin?
Your excavator hydraulic fluid is too thin because it is probably not of high quality. It could also be too thin if the hydraulic system of your excavator overheats. It can start leaking. Thin hydraulic fluid can cause significant damages to your excavator’s hydraulic system as the hydraulic system will not be able to draw enough amount of hydraulic oil to the hydraulic system.
Here’s the deal: Use the correct type and amount of hydraulic fluid in your excavator hydraulic system.
14. How Often Should I Change Hydraulic Fluid in My Excavator Hydraulic System?
You need to check your excavator hydraulic fluid after every 100 hours of operation. It would be best if you’d change your excavator hydraulic fluid after every 1,000 hours of operation – assuming everything runs just fine. Also, consider checking your excavator service manual as your excavator manufacturer could probably have a different recommendation. Some excavators can stay up to 4,000 hours of operation with hydraulic fluid before the next service.
Here’s the deal: Check your excavator service manual – it provides the very schedule that you are looking for in this guide.
15. How Can I Know If the Hydraulic Fluid in My Excavator Hydraulic System is Bad?
You can tell if the hydraulic fluid in your excavator is bad when it starts foaming, getting too thin, as well as making the hydraulic pump produce abnormal noise. The fluid also gets too hot quickly. Your hydraulic fluid will over time degrade. However, some factors will accelerate the damage process, and as such you need to care for your excavator hydraulic system to prevent this from happening.
16. How Are Excavator Hydraulic Systems Maintained?
You can maintain your excavator hydraulic system by doing the following:
- First, you need to ensure that you use clean, high-quality products (hydraulic fluid and components like hydraulic filters, aftermarket pumps, etc.).
- Then, you need to do is to periodically check the level of hydraulic fluid in the hydraulic system. Doing so will help you know if there is a problem. You can choose to check the level of hydraulic fluid level in your excavator after every 100 hours of operation.
- You can opt to service your excavator hydraulic system after at least every 1,000 hours of operation, or depending on what your excavator manufacturer specifies.
- You’ll also need to repair and/or replace any worn-out excavator hydraulic system component to prevent further damage to the system.
- Consider checking for temperature changes, abnormal noise, or even leaks as they suggest that there is an issue that requires immediate attention within your excavator hydraulic system.
- Check for solid or liquid contaminants in the oil. You can also check for foam as it will suggest that there is an air leak within your excavator hydraulic system.
- Always follow the guidelines provided by your excavator manufacturer.
Bottom line: Maintaining your excavator’s hydraulic system is not hard – it only requires you to sacrifice a little bit more of your time to ensure that the hydraulic system runs well.
17. How Should I Service My Excavator Hydraulic System?
Servicing your excavator hydraulic system is a delicate process that requires attention. Leading experts recommend allowing certified mechanics to do the servicing for you as any mistake could prove fatal to your excavator hydraulic system components. Also, as the certified mechanic does the servicing for you, ensure that they strictly follow your excavator’s service manual guide provided to you by the manufacturer. It is necessary to do so as different excavator types and brands have different specifications.
Check this out: You’ll also need to ensure that your excavator gets serviced using high-quality products, that is, filters as well as hydraulic fluid. Your mechanic will notify you of the best hydraulic fluid to use in your local region depending on the environmental temperature.
Remember that the hydraulic fluid should be filled to the recommended optimum level – it should not exceed as it could leak and thus degrade the environment.
18. How Are Excavator Hydraulic Systems Repaired?
You can repair your excavator hydraulic systems by first carrying out a proper diagnosis as outlined earlier in this guide. After carrying out a proper diagnosis, you can repair any component that is damaged or replace a component that cannot be repaired such as seals and valves. It would be best if your excavator hydraulic system would be repaired by a certified expert. The expert can determine whether the damage is normal, or if there are any underlying issues within the hydraulic system.
19. How Should I Replace Damaged and/or Worn-out Excavator Hydraulic System Components?
You’ll need to replace any worn-out or damaged excavator hydraulic system components by strictly adhering to your excavator manufacturer’s specifications. Replacing any component within the hydraulic system also requires attention and focus. It would be best, yet again, to let a certified expert help you complete the replacement process.
Any minor mistake could render your whole excavator hydraulic system faulty, weak, or even damage some components in extreme cases. For example, should your excavator hydraulic pump get installed the wrong way and starts spinning in the opposite direction, your shaft seal will get damaged, and it will affect both the pump and the motor.
20. Where Can I Get the Best Excavator Hydraulic System Components for My Excavator?
As you’ve read earlier on in this guide, your excavator hydraulic system components are best acquired from KS XuGong, the leading aftermarkets parts manufacturing company across the globe. We are based in China.
Here’s the deal: KS XuGong offers the best deals at affordable prices. We allow you to reach out to us with your requirements as well as your estimated budget for the same. Then, we try to harmonize the two parameters and respond to you with a free quote.
Now, you can be sure that we manufacture quality aftermarket excavator products as we strictly adhere to OEM aftermarket practices during the manufacturing process. These practices mean that our excavator parts are fully interchangeable with the original ones.
You can be sure that we will not delay when it comes to shipping your parts to your desired location. We guarantee you this because we have been in business for over eleven years now, and we’ve managed to grow to a point where we have over 10,000 quality excavator parts in stock.
We’ve also managed to establish a close working relationship with the world’s leading logistics companies, the likes of DHL, TNT, FedEx, Wells Fargo, etc. These companies guarantee on-time delivery, as well as damage-free delivery of your desired parts. It is important for you to receive your excavator parts, such as the hydraulic fluid filter, free from any physical damages.
Check this out: Before shipping off your ordered excavator hydraulic system components to your desired location, you’ll need to clear your payment first. You can pay us using the following platforms:
- Western Union
Our service reps are also available 24/7/365 to help you out with any issue that you may have. They’ll offer you timeless advice on how to handle different excavator repair situations, how to best handle your excavator for maximum productivity as well as efficiency, etc.
All you need to do is to reach out to us with your excavator’s make and model, your requirements, your estimated budget, and leave the rest to us.