Diagnosing Pump Problems on Construction Equipment
A failing hydraulic pump often comes after many signs point to the larger issue.
So, to avoid a failing pump, be vigilant when the most common problems start occurring, and follow the basic four troubleshooting steps:
- Identify the specific problem
- Gather information from schematics
- Adjust and verify the diagnosis
- Plan and schedule maintenance
To help identify pump problems as soon as possible, let’s first look at some common pump issues found in construction equipment, and which ones often lead to pump failure.
Next, let’s get to diagnosing and planning a simple maintenance plan to keep your pump and heavy-lifting hydraulic equipment in optimum shape.
Identifying Problems That Lead to Pump Failure: Environmental and Contamination
Failure modes for hydraulic hoses and cylinders are visible. However, failure modes for Hydraulic pumps can be a little more complex to diagnose, as they are critical components of machines such as excavators that work under vigorous conditions.
Pump issues can come gradually and subtly, resulting in pump failures that have cascading effects throughout the entire hydraulic system.
Let’s first identify the two likely culprits that can cause hydraulic pumps on construction equipment to go into failure mode: environmental and contamination.
- Environmental Damage – As construction equipment is typically left outside to face the elements. A piece of equipment can see temperature ranges between -30F to 120F with humidity levels between 24% to 95% while being exposed to UV, rain, ice, and dirt. Hydraulic hose assemblies will degrade over time due to these exposures, becoming less pliable and a source for failure & safety risk while in operation. The best solution is a consistent preventative maintenance schedule consisting of inspection and replacement before failure.
- Harm from contamination - Contamination enters the hydraulic system due to moisture, which is often attributed to temperature and humidity level changes. Second, dirt enters a hydraulic system from the environment in which the equipment must operate. Filters often become clogged and lose their ability to protect the other components within the system. Again, a consistent preventative maintenance schedule consisting of inspection and replacement before failure.
The link between leaving construction equipment out in the elements and contamination are to blame for a slew of issues that can eventually lead to pump failure.
Whether caused by environmental factors or because of contamination, here are four common signs that can help identify why your pump is in trouble:
- Failing seals - A hydraulic pump within construction equipment contains a high level of pressure that exerts force on seals in the pump, which can begin to leak (internally or externally) or fail. Even minor leaks in seals can lead to loss of fluid and create issues in the system.
- Overpressure and overloading - Every hydraulic pump has an upper limit, and if it is subjected to over pressuring and overloading beyond what the manufacturer has specified, the pump is more prone to damage and failure.?
- Air in pump and in fluid – Excess air inside the pump can lead to inefficiencies in the pump and force the pump to work harder or erratically.
- Low oil or too much oil – Pumps that run construction equipment with too little or too much oil even for a brief time can cause the pump to overwork, lead to increases in working temperatures, or create conditions for non-uniform movement.?
Knowing some of the most common signs that a hydraulic pump may be in trouble and checking often is a great first step to diagnosing any problems early. Check schematics for verifying issues such as pressure, temperature, and oil discrepancies.
Verifying and Correcting Pump Problems
Wondering if these issues are affecting your pump after detection? Here is a short list of adjustments that can be made to verify and correct common problems that can lead to pump failure.
Common signs of pump issues | Possible causes/corrections |
Leaks in seals or connections | Inspecting the pump for the presence of oil can lead to the early discovery of problems. If the issue is simply a loose connection, a quick tightening can often stop a small issue from growing. |
Loud noise, whining, or knocking | Any new or increasing sounds are often caused by either cavitation or aeration in the pump, but a close inspection can determine whether an operational fix can be made. |
Excessive heat | An overheated hydraulic pump is both a sign of current trouble and a cause of other growing problems. |
Erratic movement | If you notice non-uniform movements in a machine, take time to rule out the hydraulic pump. |
Investigating these early signs may lead you to realizing that a hydraulic pump failure is possible.
Knowing the common causes of pump failures to look out for is a proven way of proactively discovering developing issues and correcting them before it’s too late.
Construction Equipment Pump Maintenance
With all systems a go, you may want to include the problem in a scheduled preventative maintenance program.
Besides avoiding pump and system failures, a properly maintained hydraulic system allows equipment to operate efficiently.
A hydraulic pump on an excavator, wheel loader, dozer, or other construction equipment is often ignored until it starts to act up and causes issues.? As we have already explained, subtle issues can lead to big ones, so maintenance is key.
For example, let’s consider what maintenance looks like on an excavator’s hydraulic pump.
When working at full efficiency, the excavator’s pump supplies the flow and pressure throughout the machine. As the pump spins, oil travels through the system and allows the excavator’s tracks, boom, arm, and bucket to work.
To maintain this level of efficiency, an excavator’s pump requires little to no maintenance. However, the hydraulic pump still needs to be checked periodically to ensure its mounted securely and working properly. Other components need daily management.
Here are four suggested maintenance considerations to protect pumps within excavators:
- Fluid management - Oil should flow through an excavator seamlessly, and additives should be considered to help keep that oil clean. Use the correct, quality hydraulic oil and keep track of how often it changes and follow the maintenance schedule found in the machine’s operation manual.
- Daily maintenance – A daily machine walkaround to check the machine’s overall condition is vital. Look specifically for any leaks, damaged hydraulic pipes, or hoses. Make sure hardware is secured and tighten anything that isn’t.
- Warmups and cooling systems – A gradual warmup procedure allows the hydraulic system to reach its ideal operating temperature in cold weather. In hot weather, operators should be more diligent. about keeping the hydraulic cooling system clean to avoid cracks in rubber hoses and other hardware.
- Protect components - Closely examine oil cooling systems, machine panels, and cylinder guards and make sure they are functional, clean, properly installed, and mounted correctly.
Denison: The Right Pump for Construction Equipment
Hydraulic Parts Source specializes in four product lines:?Vickers, Denison, the Rexroth A10VSO series, and Servo and Proportional valves.
Denison’s high-quality and flexible pumps have a reputation for withstanding the test of time, and being especially useful when applied to construction equipment.
Even with the best quality Denison pump, however, issues can come gradually and subtly, resulting in pump failures that have cascading effects throughout the entire hydraulic system.
Troubleshooting begins by first identifying any problems and information-gathering on common issues with pumps that lead to failure.
Next, consider making adjustments and planning for daily and routine maintenance to keep construction equipment working efficiently. Pumps on construction equipment can be complex to diagnose later, so being vigilant is key.
Hydraulic Parts Source is a leading fluid power remanufacturer, and we’re ready to serve you. Contact us today to experience OE quality for a fraction of the time and cost by calling (888) 477-7278 or get a quote by emailing sales@hydparts.com.