Troubleshooting Your Hydraulic System

When your hydraulic system stops working, no matter the cause, it can bring productivity to a grinding halt (both literally and figuratively). Troubleshooting and tracking down the problem will take skill, experience and common sense. There are a few basics that anyone can handle, however. The basics of hydraulic troubleshooting serve as a reminder to keep it simple and take time to do each step. This will save money and time in the long run.  

Preparing for Troubleshooting

Before you even begin the troubleshooting process, it’s important to know what the problem is. This means you have to ask questions before you start. Some basic questions might be:

  • How long has this been happening/When did it start?
  • When did you first notice the problem and what was happening? (start up/shut down/heavy load/temperature change/etc.)
  • Have there been any recent changes to the system, such as maintenance, modifications to the settings, or repairs?
  • When was maintenance last performed?

Once you have as much information as you can gather, pull the hydraulic schematics for reference. It’s important to know that you should not attempt troubleshooting without this! The schematics provide valuable information about flow and pressure in the system.

Common Problems

There are a number of issues that commonly prevent hydraulic systems from working properly, such as an inoperative system or overheating hydraulic fluid. In any basic troubleshooting, it’s key to look at the most typical issues that arise in hydraulic systems first.

System Inoperative

When your hydraulic system is inoperative, there are several things that can be checked. First, you must verify the hydraulic fluid levels and check for leaks, as they can lead to significant loss of hydraulic fluid. Filters are also a common problem, because if they are dirty or clogged, it can seriously impact performance. Check your hydraulic lines for restrictions such as collapse or clogging. Be sure you do not have any air leaks affecting the suction line. Also inspect the pump itself; if it is worn, dirty, or out of alignment, it will affect system performance. The drive can be a source of issues if belts or couplings are slipping or broken. 

Slow Operation

If your hydraulic system is working more slowly than normal, it could be as simple as the hydraulic fluid being too thick, which may be due to cold temperatures or the use of an inappropriate hydraulic fluid. Air trapped in the system can be a problem, as well as restrictions in the line, due to dirty hydraulic filters. Another potential issue is badly worn hydraulic components such as pumps, motors, cylinders, and valves.

Erratic Operation

When a system is operating in an erratic, unpredictable manner, it can be very frustrating. One of the most common causes for this is air trapped in the system or hydraulic fluid that is too cold. Damaged internal components, such as bearings and gears can also be a reason, although it is a bit less common.

Excessive Noise or Vibration

Something that almost anyone who works with hydraulic equipment has experienced is excessive/abnormal noise or vibration. The pump being noisy calls for a check that the oil level is sufficient, the correct type of fluid is being used, and that the oil is not foamy. If oil is foamy, that informs you that there is air in the fluid. This can lead to cavitation and expensive damage. It is also wise to verify that the inlet screen and suction line are not plugged. For both pumps and hydraulic motors, there can also be internal issues, namely worn or misaligned bearings. Noise and/or vibration can also mean you need to make sure the couplings are secure and tight. Keep in mind that pipes and pipe clamps can vibrate if they are not secured properly, so take a moment to check them over if none of the other checks show an issue.

Overheating Hydraulic Fluid

Excessive heat is never a good sign in a hydraulic system and often leads to a system working at sub-optimal levels. One of the primary purposes of hydraulic fluid is to dissipate generated heat, but the system should not be generating enough heat to cause the fluid to reach high temperatures.

There can be many causes behind hot hydraulic fluid, starting with contaminated hydraulic fluid or fluid levels that are too low. There may be oil passing through the relief valve for too long at a time; in this case, the control valve should be set to neutral when it is not in use. Worn out components within the system can also lead to excessive temperatures due to internal leakage. Restrictions in the line or dirty filters can result in hot hydraulic fluid or if hydraulic fluid viscosity is too low, it can lead to overheating as well. Finally, there may be a need to make sure that the oil cooler is functioning correctly and that the key components are clean enough for heat to radiate away from them.

No Fluid Flow

Having no flow within the hydraulic system is a serious issue that can have several different sources. The first step is to determine exactly where the fluid flow stops, such as failure of the pump to receive fluid at the inlet (usually the result of a clogged line or dirty strainers) or a failure for fluid to exit the outlet, which could be due to a pump motor that needs replacing, a sheared coupling between the pump and drive, or a pump/drive failure. It would also be a good idea to make sure the pump rotation is set correctly and the directional valves are in the correct position. The most expensive problem would be a damaged pump that needs to be replaced or repaired.Getting your hydraulic system back in working order can be a time consuming process. At Yarbrough Industries, we understand the importance of having a functional, efficient hydraulic system. We know that downtime is a price that you can’t pay in both money and time. That is why we offer comprehensive hydraulic services on-site troubleshooting and repair. Our team of experienced technicians can work on motors, pumps, valves, cylinders, and systems. When complex repairs are called for, we have a full machining center and certified welders. We also offer customized maintenance plans tailored to your needs and your equipment. Contact us today to find out how Yarbrough Industries can help keep your hydraulic systems operating efficiently.

Choosing the Correct Hydraulic Hose

Any hydraulic system relies on having quality hoses to continue working effectively. That means selecting the right one could make the difference between operating an effective system or dealing with defects and potential damage. 

When looking at hydraulic hoses, they appear relatively simple and possibly even interchangeable. However, hoses are actually multi-layered, sophisticated tools designed and manufactured for specific applications. Figuring out which hose is right for your system depends on several key factors, including size, temperature, compatibility and choosing the right hose fitting connection.

Choosing a Size

If a hose is to function optimally, the inside diameter must accommodate the correct amount of hydraulic fluid, minimize pressure loss and avert heat generation or excessive turbulence, both of which can damage the hose. The “Dash Numbers” measuring system is the hydraulics industry standard used to indicate hose size and the proper accompanying couplings.

Determining Your Temperatures

When looking for a hose, it will need to be able to accommodate two temperature areas — that of the hydraulic fluid and that of the environment in which the hose exists (ambient temperature). Hoses that cannot withstand both the minimum and maximum temperatures of the fluid, as well as those not designed to work near hot manifolds, are likely to fail.

Ensuring Compatibility 

Typically, replacement hoses should be duplicates of the original hoses. In some circumstances, however, using a different type of replacement hose might actually be desirable. This is especially true if the hose failed prematurely due to excessive abrasion, unusual mechanical loads, routing challenges, temperature fluctuation or some other environmental factor. With advancements in hose engineering, there may be a better hose available.

As you read in the first paragraph, typical hydraulic hoses consist of numerous tubes, including one inner, one outer and several reinforcement layers. Hose tubing must come in direct contact with the fluid it carries, so it is important to ensure that the inner tube is compatible with the system’s fluids in order to perform reliably. Furthermore, the threads and mechanical interfaces of ends and couplings need to be compatible with the hoses and other system components. If they’re not, leaks and other hose failures can occur.

Choosing the right hose fitting connection 

The most important factor in choosing a replacement hydraulic hose is the system pressure. It is vital that you know your system’s precise working pressure — including pressure spikes — when choosing a hose to ensure it will function properly. Finding the correct hose tube and the right fittings will help you avoid future hydraulic hose failures, which may include leakage, cracking or whipping.

Delivery of hydraulic fluid is all about volume and velocity. Any replacement hose needs to be properly sized to efficiently and effectively transport hydraulic fluid. If for any reason the system has been altered, you need to determine the hose I.D. by consulting with an expert.

For more information about hydraulic hoses, or if you need assistance choosing the right hose fitting connection for your system, contact us today!

Why Do Hydraulic Cylinders Fail?

Hydraulic cylinders are used in many industrial applications including a variety of manufacturing equipment and engineering vehicles, or civil engineering equipment. Hydraulic cylinders may encounter challenges for a variety of reasons. Regular equipment inspection, and a good preventive maintenance plan will help decrease the chances of cylindrical failure due to the following reasons:

  • Seal Leakage: One of the most common reasons we see cylinder failure is due to seal leakage. This can be caused by a variety of reasons, from something as simple as an incorrect fitting to inappropriate metalwork clearances. Some other causes of hydraulic cylinder seal leakage might be something like markings on seal grooves or corrosion.
  • Contaminated Fluid: Fluid contamination is another major reason for the cylindrical failure. Abrasive particles that are trapped in a contaminated fluid can bring severe damage to the piston rod or seal surface. Airborne contamination is usually induced by a faulty wiper seal.
  • Damaged Rod Bearings or Piston Rods: It is also common to see damaged rod bearings or piston rods that lead to hydraulic cylinder failure. This is caused due to improper alignment between load and the cylinder, thereby resulting in a bending, or side loading.
  • Internally Corroded Barrel: Contaminated fluid inside a cylinder can lead to internal corrosion. This can be avoided by blocking the water ingress inside the cylinder. However, it may be a sign that cylinder is being used in an environment, where it should not be used. It’s important for an expert to determine what the cause of the corrosion is and how it should be remedied. 
  • Broken Eye Bearing: If a cylinder handles loads above its specification, you may encounter a broken eye bearing.  These may also be caused by a shock loading or a sudden impact due to high pressure.
  • Extreme Temperatures: This factor may affect hydraulic cylinders  by limiting the choice of seal geometries or materials. It can also cause less lubrication and/or seals with cracked sides or brittle appearance.
  • Chemical Contact: Certain chemicals can cause cylinder failure when they come in contact with the seal. While verifying beforehand can prevent this, it is often forgotten, leading to compatibility issues and numerous problems. 

There are various other reasons for a cylindrical failure ranging from high pressure conditions to side loading and more. However, if you notice any symptoms of hydraulic cylinder failure, you can immediately contact an expert preventative maintenance service such as Yarbrough Industries.