what causes a hydraulic pump to get hot brands

Hydraulic pumps generate heat while they run. However, hydraulic fluid temperature should never exceed180 degreesF (82 degrees C) under normal working conditions. If your hydraulic pump temperature rises above this, then that is a sign that your pump is likely overheating. One of the most common causes of hydraulic system failure is a hydraulic pump that runs too hot or overheats.

When a hydraulic pump runs at a too-high temperature for too long, it can ultimately lead to pump failure. Once a hydraulic pump begins to fail, it can potentially damage the entire hydraulic system by sending contaminants and debris into the system that can damage its other components.

In addition, when some hydraulic fluids are subject to high temperatures, they can thin and lose their viscosity. When hydraulic fluid is too thin, it is much more likely to leak, and fluid that has lost its viscosity cannot lubricate your pump properly. Extremely hot fluid can also damage pump seals, further increasing the chance of a pump leak.

Some hydraulic fluids thicken and oxidize when exposed to high heat instead of thinning. When hydraulic fluids are too thick, they can restrict flow throughout the entire hydraulic system, which leads to your system heating up even further.

The sooner you determine why your hydraulic pump is running hot and repair the cause of the problem, the less likely your hydraulic system will develop irreversible damage or fail completely.

Hydraulic pumps overheat for many reasons. Just a few of the most common causes of hydraulic pump overheating include: Contaminated hydraulic fluid. When fluid has debris and dirt, contaminant particles can quickly build up on hydraulic system filters, leading to filter clogs. Your pump has to work harder to pump fluid through clogged filters, which leads to overheating.

Aeration. Air leaks at seals and fittings on your hydraulic system components can lead to air entering your system and forming bubbles in your fluid. Air bubbles generate heat when your system compresses them and then pass this heat into the surrounding fluid, overheating it.

Low reservoir fluid. Since your hydraulic system releases some of the heat it creates into reservoir fluid, a low reservoir fluid level can contribute to overheating.

Blocked or damaged heat exchanger. This component is also an important part of your hydraulic pump"s cooling system. If it is blocked or damaged, then it cannot help remove heat from your pump properly.

Once your hydraulic pump beings overheating, you need to find the cause of the problem and repair it. That way, your pump can begin operating within its ideal temperature range again.

If your pump overheats due to fluid contamination, then either remove all contaminants from existing fluid or remove the current contaminated fluid from the system and add fresh fluid. Be sure to filter all fresh hydraulic fluid before you add it to your system because even this fresh fluid can contain contaminants. Also, replace your fluid filters on a regular basis to prevent the overheating that can occur when these filters become blocked with debris.

If air has entered your system through leaky seals and fittings, then have a hydraulic system repair expert inspect and replace or tighten these fittings. Have a hydraulic system repair expert also look at heat exchanger damage to determine if the exchanger needs repairing or replacing.

Finally, be sure to check your system"s reservoir fluid level on a regular basis. Add new fluid when necessary to help this reservoir perform its important task of helping to keep your pump cool.

Your hydraulic pump should always operate within its ideal temperature range. If your pump is running hot, then contact the hydraulic pump experts at Quad Fluid Dynamics, Inc., forhydraulic pump diagnosis and repairtoday.

Is your hydraulic pump getting excessively hot during normal operation? Pumps do generate heat when running, however they are designed with specific heat parameters in mind. Overheating is an abnormal condition that leads to destructive issues such as thinning of hydraulic fluid, which leads to reduced lubrication, metal-on-metal contact of moving parts. And accelerated pump wear and failure.

Therefore it is never a good idea to ignore a pump that is exceeding its heat parameters under normal load. There are a number of factors that contribute to an excess buildup of heat and in this article, we’ll explain some of these issues.

Hydraulic fluid viscosity refers to the thickness or “resistance to pouring” of your hydraulic fluid. This is very important to the correct operation of your pump. The fluid not only transmits the power that moves your drives and actuators. It also lubricates internal components and removes heat from the system. Hydraulic fluid is designed to operate at a specific temperature range. As it heats, it becomes thinner and eventually it will lose the ability to lubricate moving parts. The increased friction may cause the pump to heat up, and naturally increased wear will be taking place when this is happening. On the other hand, hydraulic fluid that is too thick flows less efficiently within the system, which also results in heat buildup.

Fluid that is contaminated with dirt, debris, water and other impurities may cause heat build up in a few ways. Blocked fluid filters, pipes and strainers place undue load on the pump or even lead to pressure drops on the back side of filters that cause cavitation.

Low fluid levels can result in a condition in which not enough flow is reaching the critical hydraulic components and moving parts. This is known as oil starvation and just like running your car without oil, it will increase metal-on-metal friction and lead to increased heat and wear. Oil starvation can also be caused by clogged hydraulic filters, incorrect fluid reservoir design.

Cavitation is the rapid formation and implosion of air cavities in the hydraulic fluid. When these air cavities collapse under pressure, they generate a lot of heat. In fact, temperatures can reach up to 2700 degrees C at the point of implosion! Not only does cavitation compromise the lubrication properties of the oil, the excessive heat that is generated is extremely damaging to the hydraulic pump and the system as a whole. Attacking hoses and seals and causing metal components to expand and wear.

This happens when air makes its way into the system via air leaks at points like pump seals, and pipe fittings. And what happens next in a hydraulic system? Compression! Air generates heat when compressed, which naturally leads to an increase in temperature if left untreated. In extreme circumstances it can also lead to ‘hydraulic dieseling’ whereby compressed air bubbles actually explode in the same process that powers diesel engines. This is not good and leads to degradation of the fluid and damage to system components through loss of lubrication and burning of seals.

As pumps wear, the internal leakage or “slippage” increases. Essentially, fluid is able to make its way past tight fitting components, which reduces the efficiency of the pump, but in addition, as this occurs, fluid moves from a high pressure to a low pressure without doing any mechanical work, since according to the laws of physics energy cannot be destroyed, it is instead converted into heat.

A build-up of excessive heat is a symptom of hydraulic pump problems, but it is far from the only signal that there may be something wrong. There are other important warning signs that you should pay attention to. These include unusual noises, pressure problems and flow problems. Each of these symptoms provide clues about any potential pump problems that need to be addressed - so it’s important to familiarise yourself with all of these issues. To help, we’ve created a downloadable troubleshooting guide containing more information about each of these issues. So that you can keep your system up and running and avoid unplanned downtime. Download ithere.

Overheating isa frequent problemwithin hydraulic systems that may be determined by specific components. Thisinternal problem lies within the pump and causes a hydraulic system to overheat in the following ways:

Contaminated hydraulic fluid is a common cause for a Hydraulic system to overheat. This can occur when the container is not sealed properly which causes dust, dirt,debris,or moisture to contaminate the fluid.With hydraulic systems running at higher pressures and more efficiently than ever before, it is important tomonitorthe cleanliness of one’s hydraulic fluid. Reducing contamination can decrease damage andwillallowoneto get the most out oftheirequipment.

Wrong valve calibration could resultin pressure difficulties which can cause a hydraulic system to overheat. The main cause of this is when a facility’s plant design changes and maintenance recalibrate the pressure relief valves for the updated operating pressure. If maintenance adjusts the pressure,and it stilldoes notsolve the problem, the pressure relief valve may have to be replaced entirely. Erosion to a valve is a common occurrence as dirt and debris settle and collectthroughout time. Maintaining the correct pressure will help your system keep up with production and not slow down.

Aeration in a hydraulic system can bea common issueand is caused by an outside air leak in the suction line.The pressure used in the suction line of hydraulic systems is below atmospheric pressure, so oilcannotleak out, but air can leak in.This will occur when there are loose, leaky seals and fittings which will allowtheair to seep in.Aeration can have severalnegative effectson top of overheatingsuch as increasedpump cavitation, excessive noise, and loss of horsepower.Some symptoms of Aeration may include foaming of the fluid, irregular movements, and banging and or loud clicking noises as the hydraulic system compresses and decompresses.

A blocked heat exchanger is significant toheating one’s hydraulic system, while cooling it down is just as important.Aninfrared thermometer isan effective wayto checkthe temperatureof a heat exchanger. Theadjustments can be made according tothedesign of theflow rateof oil.Make sure to replace the fluid fitterslocatedin the pumpon a regular basis to ensure theywill not get blocked andoverheat.

Oil Type plays a critical role inany hydraulic system. The wrong oil will not only affect the performance of the system but also cut down the lifespan of the machine. Theoil Viscositydeterminesthe maximum and minimum temperatures in which a hydraulic system can safelyoperate.Thin oils have a lowviscosity andflow more easily at low temperaturesthanthicker oils that have a higherviscosity.If the oil is too thin it can cause internal friction whichcreates heat and cancausethe system to overheat.

Low reservoir fluid is a common cause ofoverheating in hydraulic systems as itreleasesbuilt-upheatfrom the machineintothe fluid. Not having enough reservoir fluid cancontribute tocavitation andultimate damage to the pump.

Hydraulic pump failure candamage the entire hydraulic system.When a pump fails,debris, dirt, and grime kick out downstreamand can affect theoil,filter,valves, fluid, and actuator.Contactour KICK@$$ hydraulic system repair professionalsat Allied Hydraulic to avoid these problems.

You can use multiple different upgrades and tuning methods on hydraulic systems. Many users will invest in upgrades that promise more flow and speed. The issue with these upgrades is that they"re not always fit for the hydraulic systems they"re applied to.

Since everything needs to stay in balance, you must make sure your upgrades match the entirety of your hydraulic system. For example, a higher flow pump can help give increased capabilities to a hydraulic system, but did you also check to see if the system"s hoses and piping can handle that increase in flow?

The increased flow can hit your smaller hoses hard and require more pressure just to get through them. This goes for any part of the hydraulic system that isn"t readily capable of handling more flow.

If a component becomes a flow throttle, the increase in pressure at the site can cause an overall pressure drop in the system. Also, the energy required to force flow will directly translate to an increase in heat, which lowers the systems efficiency and effectiveness.

When you make upgrades, also ascertain if you need to change other components. In the example of the higher flow pump, you can simply increase your hose size, and that makes all the difference.

Hot hydraulic fluid can be one of the causes of an overheating final drive motor. If your hydraulic fluid is running at a higher than normal temperature then it can cause problems for your entire hydraulic system. In this Shop Talk Blog post, we are going to talk about what can cause hydraulic fluid to overheat.

Another potential source of problems is a relief valve. If a relief valve fails or is out of adjustment, it can affect the system pressure. Changes in system pressure, as we just discussed, can also affect the temperature of the hydraulic fluid.

If you use the wrong type of hydraulic fluid for your machine, that, too, can cause the fluid to overheat. If that’s the case, then you need to replace the hydraulic fluid to fully address the problem.

If the oil cooler gets dirty or becomes plugged, that can also cause hydraulic fluid to run too hot. The solution to this problem is to take some time to clean off the oil cooler fins. Another potential source of problems is the cooling fan. If it is damaged, or if the fan belt isn’t at a right tension, then it can be the source of hot hydraulic fluid.

Another source of overheating lies in the level of your hydraulic fluid. If your reservoir is low on hydraulic fluid, that can cause the fluid that is in the system to overheat. However, that points to another problem: a leak somewhere. Don’t just top off the hydraulic fluid level, but also check for leaks that could be responsible for a low level of fluid.

If your hydraulic system is running too hot, then you need to track down the source of the problem. Hot hydraulic fluid will lead to damage and is a sign that something is wrong and needs to be addressed. If left unaddressed, then expensive issues and unnecessary downtime are bound to be the results.

is your partner in providing new or remanufactured final drive hydraulic motors from a single mini-excavator to a fleet of heavy equipment. Call today so we can find the right final drive or hydraulic component for you, or check out our online store to.

Every hydraulic system is adversely affected by excessive heat. The impact of excessive heat in a hydraulic system can be particularly insidious because of the subtlety of its effects. Over time, excessive heat can lead to system damage due to seal failure as well as hydraulic fluid breakdown. It is important to remember that hydraulic fluid is critical to protection of the metal components in any system and its degradation will lead to shorter component life.

While good design techniques can be employed to reduce overall heat load in a system, it is generally a mistake to believe that good design alone can prevent overheating in the absence of a cooler. Learning what causes excessive heat, and how to reduce that heat, will extend your system components life expectancy. Reducing heat can be as easy as adjusting a relief valve, or as complex as performing a complete heat load analysis, and adding in the proper cooling system. There are many reasons for hydraulic overheating, but here are three that we see most often;

User improvisation: We often hear of systems that have been running smoothly for years, and now all of a sudden they begin running hot. In many cases this is caused by someone making a system adjustment. One of the more common adjustments made is to the pump compensator to achieve more pressure on pressure compensated variable volume pumps. If the adjustment is made, and it exceeds the main relief valve setting, the excess flow is dumped over the relief valve which induces heat into the system.

Improper system design: Pressure drop is another heat generator when components are not sized properly. When it takes too much pressure to allow flow through your valves, pipes, hoses, filters, and any other system components, this wasted energy generates excess heat.

Improper cooling selection: A cooler is almost always required regardless of your system design. This is especially true for mobile machines where reservoir space is limited so you have a smaller amount of available hydraulic oil along with rapid recirculating of that oil. Heat load and available flow are some of the things that have to be accounted when selecting an external cooler. In addition, there are many different types of coolers that fit different systems requirements.

Choosing the correct cooler for your system can be a complex and complicated process. Excessive heat in a hydraulic system will attack every part of that system, and shorten the life of every component. Here at Cross Company, and our Mobile Systems Integration Group, we have a team of engineers that specialize in complete hydraulic systems design to achieve maximum efficiency and proper cooling selection.

When hydraulic oil is getting overheated, there could be several common causes that also cause the system to overheat. First, it is crucial to understand the type of hydraulic system you are using to begin troubleshooting why the system is overheating.

The first cause of hydraulic oil overheating is when the hydraulic equipment system parts and components are nearing the end of their useful lifespans. As they degrade, due to increased internal leakage, they have to work harder to maintain the desired system pressure.

For example, your hydraulic pump is wearing out and needs to be replaced. Due to internal wear pressurised fluid escapes from the high pressure side to the low pressure side generating heat increasing the temperature of the hydraulic fluid and causing circuit overheating.

It is understood that you may want to make system upgrades or changes to customize the system to reflect your specific needs. However, when you do not consider the entire system, it can cause the system to work hard, give off more heat, and increase hydraulic oil temperatures, leading to circuit overheating.

For instance, you may want to increase the fluid flow rate through the system. However, you did not account for the size of hoses and tubing to accommodate the higher flow rates. As a result, the system has to work hard to force the increased flow rates through incompatible hoses and tubes, resulting in more heat generation and fluid overheating.

Tweaking your hydraulic system is perfectly acceptable to optimize its performance. However, where many people go wrong is they only adjust one part of the system and fail to think about how the adjustment will impact other parts of the system.

For example, suppose you make an adjustment to the pump compensator and increase the pressure yet fail to also make a similar adjustment to the relief valve. In this instance the relief valve will blow off more frequently generating more heat and therefore increasing the circuit fluid temperature.

Every component in a hydraulic system imposes a load on the pump, this is referred to as the pressure drop across the particular component. The figure will vary depending upon the flow rate and the energy lost from the fluid due to the pressure drop is converted into heat. If the overall pressure drop across all the components in the circuit unexpectedly increases so the heat generated across the circuit will also increase.

If the fluid is not cooled to compensate for this the fluid temperature continues to increase as the other parts and components generate excessive heat.

If there is dirt, sludge, debris, or water in the hydraulic fluid, the system will generate more heat as it attempts to compensate for the contaminants and push the fluid through the system. Therefore, it is always vital to check your fluid for contamination and change it and or improve fluid filtration when required.

After troubleshooting overheating problems, if you have determined it is not due to the four common causes mentioned above, then there are two general ways you can resolve fluid overheating problems. You can either increase the reservoir capacity to dissipate heat or decrease the amount of heat being generated by the system.

Another way to increase the heat dissipation is to inspect the current heat exchangers, if they are being used, and make the appropriate adjustments. In some cases, you may want to install additional heat exchangers to help reduce the fluid temperature.

In addition, check the airflow around the reservoir as the higher the airflow the more efficiently the reservoir radiates the heat from the fluid held inside it.

To find hydraulic parts, components, and accessories to help you resolve hydraulic oil overheating problems, or if you require assistance in troubleshooting system overheating, please feel free to contact White House Products, Ltd. at +44 (0) 1475 742500 today!

It’s that time of year again and all over the country there are hydraulic systems overheating.  Some of them overheat every summer, but most of them usually just run a little warmer with increases in ambient temperature.  What is causing it?  Often a dirty or poorly placed heat exchanger can be the culprit.  Sometimes a bypassing check valve across the heat exchanger can make the system overheat.  Unless the design of the system has been changed in some way, it is very unlikely that adding a heat exchanger is the answer.  Systems that overheat are simply not operating efficiently and there is usually an easily corrected cause.  Here are four of the more common causes of overheating that we find.

By far the most common cause of overheating that we find is an improper adjustment.  On machines that usually do not overheat but are overheating now, this is the first thing we look for.  The most common component that gets out of adjustment is the pump compensator.  It is imperative that the compensator be set below the system relief valve.  But for whatever reason, someone decides that the system would run better at a higher pressure.  The compensator setting then gets increased, but the relief valve setting does not.  Once the compensator setting approaches the relief valve setting, the relief valve starts to crack open and dump oil flow to tank.  The more the compensator setting is increased, the more the relief valve opens and the more flow returns to tank.  Instead of varying its flow to meet the demands of the system as it is designed to do, the pressure compensating pump moves to full stroke behaving as a fixed displacement pump.  Any flow not used to move a load returns to tank through the relief valve.  At system idle, ALL of the pump flow returns to tank.  Since the resulting pressure drop doesn’t do any work, virtually all of the energy going into the system is converted to heat causing the fluid temperature to soar.

Changing the system pressure is usually a bad idea.  Most systems have designer recommendations for system pressure and a lot of design criteria are taken into consideration to determine the optimum system pressure.  Often the pressure is increased in an attempt to speed up the machine but this is a very inefficient way to accomplish this.  Flow rate, not system pressure, determines the speed of the actuator.  Yes, turning up the pressure will often also increase the flow, but the more efficient way is to open a flow control or raise the setting of the manual volume adjustment.  In the absence of designer recommendations, we usually recommend that the system relief valve be set approximately 250 PSI above the pump compensator.

In Figure 1 above, the system is adjusted correctly.  The pressure compensating pump is capable of delivering as much as 30 GPM.  With only the directional valve on the left open, the system uses 10 GPM so the pump will stroke only enough to maintain 1200 PSI in the system delivering 10 GPM.  When the second directional valve opens in Figure 2, the pump stroke increases to 20 GPM to maintain the 1200 PSI setting.  But in Figure 3, the compensator setting has been increased to 1600 PSI.  The relief valve however is set below that amount at 1450 PSI.  In an attempt to reach 1600 PSI in the system, the pump will stroke to its maximum 30 GPM.  The system only uses 10 GPM leaving 20 GPM to dump across the relief valve generating heat.  We can calculate the heat that is generated using the formula HP = PSI X GPM X .000583 and we see that an extra 17 HP is generated.  In Figure 4, the system is at idle.  The pump will remain at full stroke however dumping its full 30 GPM across the relief valve.  This generates a whopping 25 HP in excess heat!

This is one that we find most often in systems that have been modified from their original design.  One of the more common system upgrades is a higher flow pump to increase speed, but the system piping and hoses may not get the same upgrade.  The result is that it takes more pressure just to push the oil to the actuators to do the work.  For example, 20 GPM will flow through a #10 SAE hydraulic hose at a fluid velocity of 20 feet per second, but if the hose is replaced by a #12 SAE, the fluid velocity drops to only 15 feet per second.  This simple size increase reduces the restriction by 25%.  Tight radius bends in pipe will also increase turbulence in the lines.  Whenever the system flow rate is increased by installing a higher flow pump, check pipe and hose charts to ensure the system can withstand the greater flow rate without an excessive increase in fluid velocity.  In the absence of designer recommendations, we usually recommend that fluid velocity be kept between 2 – 5 fps in pump suction lines, 10 – 15 fps in return lines and 15 – 20 fps in pressure lines (for systems up to about 3000 PSI)  Above 3000 PSI, the system designer will usually specify how many bends can be in the system piping and what radius they must be.  This avoids the necessity of exceptionally large piping in higher pressure systems.

As components wear, internal bypassing increases.  Oil that bypasses across the tight tolerances of a component undergoes an immediate pressure drop that performs no work.  Heat is the inevitable result.  The more bypassing that occurs, the more heat is generated.  Some components are notorious heat generators even when brand new.  Servo valves,  proportional valves and flow controls all generate heat from the time they are new because they always have a pressure drop across them.  So how do we know if a component needs to be replaced in order to keep the temperature down?  The best way is to routinely measure the temperature gain at various components in the system.  Keep a record of these measurements and use them to help locate troublesome worn components.

One of the primary purposes of the reservoir is to radiate heat to atmosphere.  You may have wondered why your hydraulic reservoir is rectangular in shape while most other tanks you see are round.  The most efficient use of volume, i.e. the maximum volume with minimum surface area, is a sphere.  This may be desirable in some applications, but in a hydraulic system we want more surface area to radiate heat, not less.  When a system is designed, the reservoir is sized based on a number of factors such as how much the oil level will rise and lower with the operation of cylinders, how long oil should remain in the reservoir to allow contaminants to sink to the bottom and how much heat will need to radiate to atmosphere.  If a higher flow pump is installed, the oil will not stay in the reservoir long enough to dissipate heat.  Also, when a variable displacement pump is used, oil from the pump case drain is ported directly to tank.  A higher flow pump will also have a higher case drain flow.  Most variable displacement pumps will bypass approximately 1 – 3% of its maximum flow rate.  Case flow is very hot because it is oil that has just bypassed across the tight internal tolerances inside the pump.  A higher case flow will raise operating temperature if a larger reservoir is also not part of the upgrade.

Hydraulic pumps are at the core of many essential factory operations. Unfortunately, there are numerous pitfalls to plan for, mitigate, and overcome to keep them running. Keeping up on routine maintenance is important, but the best way factory techs can avail themselves of costly, frustrating breakdowns is to understand the various catalysts for hydraulic pump failure.

The simplest way to identify the cause of pump failure is to thoroughly inspect and dissect the aftermath of the problem. In most cases, the cause of failure will be evident by the nature of the catalyst(s). Here are eight of the most common problems, some of their defining features, and how they ultimately come to fruition.

1. Fluid contamination is one of the biggest causes of hydraulic pump damage and involves debris mixing with the liquid. This debris causes friction, leading to extenuated wear on the pump itself. The result is inefficiency, culminating in malfunction.

2. Fluid viscosity issues occur when the hydraulic fluid within a pump breaks down over time. Viscosity that’s too high leads to cavitation (another catalyst for damage). Subsequently, if a tech changes and replaces fluid with a viscosity that’s too low, heat and friction become concerns.

3. Over-pressurization occurs because of excessive load on the pump itself, resulting in red-line operation that’s both unsafe and damaging. Hydraulic pumps operating under high duress for extended periods of time will likely experience component wear and premature failure, usually in spectacular fashion.

4. Excess heat can be a product of poor fluid viscosity or environmental factors. This issue is rarely a singular catalyst for pump breakdown, but it exacerbates other factors or masks other issues, such as fluid contamination.

5. Implosion invariably results in extreme failure for hydraulic pumps and is a major safety hazard. Implosion occurs when air bubbles within a hydraulic pump collapse, causing an overload of pressure to the pump that generates an intense shock.

6. Aeration occurs when hydraulic fluid traps air bubbles. The pump subjects the bubbles to pressure, causing high heat and over-pressurization when the bubbles collapse. Aeration at extreme levels leads to implosion.

7. Pump aeration pertains to air not in the hydraulic fluid, but air introduced through unsealed joints or shafts. This air quickly causes pressure instability affecting crucial parts of the pump. This can quickly lead to breakdowns — generally marked by a whine or other high-pitched sound.

8. Cavitation is a symptom of uncontrolled pump speeds, which fail to allow hydraulic fluid to completely fill the pump. It results in destabilized pressure, heat, and excess wear. Cavitation is often marked by the same type of whine or squeal as pump aeration.

Because the factors causing each of these problems differ in nature, it’s best to fully evaluate a damaged hydraulic pump to determine if more than one issue is responsible.

Maintenance is the best approach for ensuring safe, efficient hydraulic pump function. But routine service is just the start. Identifying common issues plaguing your hydraulic pumps will lead to a better quality of targeted maintenance — for example, if you pinpoint a heat issue related to viscosity, that issue may be resolved by opting for a different fluid weight.

Every piece of information learned about your pumps can translate into better care, leading to longer uptimes, fewer issues, and fundamentally better maintenance.

Having trouble identifying the catalysts for your hydraulic pump’s issues? Let the professionals at Global Electronic Services take a look! Contact us for all your industrial electronic, servo motor, AC and DC motor, hydraulic, and pneumatic needs — and don’t forget to like and follow us on Facebook!

Hydraulic systems are crucial to the operation of many aspects of modern life, from massive plants that depend on hydraulics to manufacture parts to the hydraulic system that powers a local garbage truck. As massive and powerful as these systems may be, they do have a proverbial Achilles heel: temperature extremes. Both low and high temperatures can affect the performance and efficiency of hydraulic systems, both large and small. If your system is not performing as expected, perhaps it is an issue with temperature that needs to be investigated and addressed.

When most people think of the effects of temperature on hydraulics, their immediate thought is heat; however, cold temperatures can have a devastating effect on hydraulic systems as well. Such sub-optimal operating temperatures can result from well-below-freezing ambient temperatures or the operation of a hydraulic system at high-altitude, low-atmospheric conditions. Low-temperature effects can be especially problematic for mobile hydraulic systems found on outdoor equipment during the winter months.

Elastomeric materials like rubber are commonly found on hydraulic systems of all sizes, and rubber (as well as other types of elastomers) is sensitive to cold temperatures and can behave as a brittle material when temperatures drop sufficiently low. When hydraulic equipment is exposed to cold temperatures, rubber components such as seals, fittings, mounts, and hoses can be seriously damaged during operation. It is important to check the condition of exterior rubber components for cracks or tears before starting the system and always have replacement parts on hand for rubber components just in case something is damaged.

Cold temperatures will affect the viscosity of the fluids in your hydraulic system, which means not just the hydraulic fluid but lubricants. Low temperatures will increase the viscosity of hydraulic fluid and oil, which means that it will behave as a thicker fluid. If the viscosity increases too much, the fluid will not behave normally; for example, on startup, oil with a higher than normal viscosity may not distribute evenly around critical parts fast enough to prevent damage. Keep in mind that fluids can actually congeal to the point where they will no longer flow. This will result in starved pumps, cavitation, and lack of lubrication, in turn leading to expensive damage to your hydraulic equipment and the components it is comprised of.

A wise practice is to check the fluids in your hydraulic equipment — including not just the hydraulic fluid but also engine fluid and transmission fluid — before starting it up. You are not checking the levels, but rather checking the viscosity: if the fluid is too thick to drip off the end of the dipstick, it is too viscous to function properly. Trying to run your system in that condition will seriously damage it. This increase in viscosity is also why it is important to give your hydraulic equipment a chance to warm up before use. Start up the equipment and let it idle in order to warm up the hydraulic system and the fluids that it depends on before you put the equipment to work.

In general, it is important to make sure the fluids used in the system are appropriate for the expected temperatures, taking into account atmospheric pressure if high altitude conditions are involved. Manufacturer guidance should be sought if there is any question as to what type of fluids are appropriate in cold temperatures.

When hydraulic fluids and lubricants are exposed to high temperatures for extended periods of time, the fluids will begin to experience permanent deterioration and a severe reduction in viscosity (i.e., the fluid will be much thinner and less viscous). The deterioration of hydraulic fluid leads to oxidation (in fact, the oxidation rate itself significantly increases with temperature) and the formation of problematic sludge. At the same time, the fluid will experience chemical reactions between degrading additives, all of which seriously compromise the performance of the fluid and the hydraulic system as a whole.

The reduced viscosity can render lubricants and hydraulic oil useless when it comes to protecting components through reducing friction, preventing abrasive damage, and minimizing the speed of wear. A change in viscosity also affects the behavior of the hydraulic fluid itself, negatively impacting the performance of the hydraulic system as a whole. Depending on a combination of pressure and temperature, some fluids may actually reach a vapor state — which will obviously lead to damaged systems and components.

While the use of a hydraulic fluid that includes a VI (Viscosity Index) improving additive may alleviate the problem of reduced viscosity in high temperatures, it is vital to remember that extended exposure to high temperatures can cause this very additive to breakdown — meaning that VI improving additives are not an easy solution to the problem. Even more interesting is the fact that extended high-temperature operation can deplete other critical additives, including foam depressants, rust inhibitors, antiwear ingredients, and antioxidants.

As fluid deterioration continues and key additives such as rust inhibitors and antiwear ingredients begin to deplete, then the components within the system (hydraulic motors, pumps, valves) will begin to experience accelerated wear. System performance and efficiency continue to drop and the system will begin generating its own heat. The result is a lethal cycle of damage to your hydraulic system as a whole and the components within. If the accelerated wear is allowed to continue unhindered, then bits of surface metal may begin to wear away, forming flakes and tiny particles that will contaminate the hydraulic fluid and exacerbate the wear.

High temperatures can result from extreme ambient temperature but are more likely to be the result of heat generation within the hydraulic system. Because heat can be so damaging to a hydraulic system, it is important to track down the source of heat generation. Heat generation commonly results from fluid flowing from an area of high pressure to an area of low pressure without any output of mechanical work. One source of such a loss of pressure is friction. High friction in the system will generate heat, and sources can include the following:

Other heat sources can include the compression of aerated fluids, which occurs when the hydraulic fluid is contaminated with air. The compression of aerated fluid within a pump can quickly lead to temperatures around 2000°F.

In some cases, the heat may not be generated by the system itself. If the hydraulic system is operating near a heat source, that could cause problems for the hydraulic system. A lack of proper ventilation can also result in elevated temperatures.

Temperature extremes will affect the performance of your hydraulic system and result in serious (and expensive) damage if nothing is done to either address the temperature issues or protect the system from the effects of the temperature. This is true whether it is a small snowplow operating during extremely cold ambient conditions or a hydraulic system in a manufacturing plant that is generating enough heat to raise its operating temperature beyond recommended limits. The most immediate effect of temperature involves the viscosity of the fluid: cold temperatures will increase fluid viscosity, making it thicker; high temperatures, on the other hand, will decrease the viscosity of the fluid. Such changes in viscosity can quickly lead to permanent damage to the hydraulic system and its components.

Changes in performance can be due to operating temperatures, and addressing those issues for high temperature situations involves some investigative work to determine the source and cause of the heat generation.

As one of our many services, MAC Hydraulics offers on-site maintenance of hydraulic systems and equipment with fully equipped service vehicles and skilled technicians who only work on hydraulics. Our experienced technicians will perform fluid analysis, inspect and replace hydraulic hoses, check fluid levels, replace filters, and perform other necessary maintenance tasks. If you have problems — including temperature issues — any time, day or night, MAC Hydraulics will send out one of our technicians to inspect, troubleshoot, and address your hydraulic problems using state-of-the-art equipment they have been trained to use. We even offer machining and welding services as needed. Whether you have a small hydraulic system on mobile equipment or a massive, complex hydraulic system that is the heart of your plant, contact us today to see how our technicians can help you develop the ideal maintenance plan for your hydraulic machinery!

Hydraulic systems are crucial to the operation of many aspects of modern life, from massive plants that depend on hydraulics to manufacture parts to the hydraulic system that powers a local garbage truck. As massive and powerful as these systems may be, they do have a proverbial Achilles heel: temperature extremes. Both low and high temperatures can affect the performance and efficiency of hydraulic systems, both large and small. If your system is not performing as expected, perhaps it is an issue with temperature that needs to be investigated and addressed.

When most people think of the effects of temperature on hydraulics, their immediate thought is heat; however, cold temperatures can have a devastating effect on hydraulic systems as well. Such sub-optimal operating temperatures can result from well-below-freezing ambient temperatures or the operation of a hydraulic system at high-altitude, low-atmospheric conditions. Low-temperature effects can be especially problematic for mobile hydraulic systems found on outdoor equipment during the winter months.

Elastomeric materials like rubber are commonly found on hydraulic systems of all sizes, and rubber (as well as other types of elastomers) is sensitive to cold temperatures and can behave as a brittle material when temperatures drop sufficiently low. When hydraulic equipment is exposed to cold temperatures, rubber components such as seals, fittings, mounts, and hoses can be seriously damaged during operation. It is important to check the condition of exterior rubber components for cracks or tears before starting the system and always have replacement parts on hand for rubber components just in case something is damaged.

Cold temperatures will affect the viscosity of the fluids in your hydraulic system, which means not just the hydraulic fluid but lubricants. Low temperatures will increase the viscosity of hydraulic fluid and oil, which means that it will behave as a thicker fluid. If the viscosity increases too much, the fluid will not behave normally; for example, on startup, oil with a higher than normal viscosity may not distribute evenly around critical parts fast enough to prevent damage. Keep in mind that fluids can actually congeal to the point where they will no longer flow. This will result in starved pumps, cavitation, and lack of lubrication, in turn leading to expensive damage to your hydraulic equipment and the components it is comprised of.

A wise practice is to check the fluids in your hydraulic equipment — including not just the hydraulic fluid but also engine fluid and transmission fluid — before starting it up. You are not checking the levels, but rather checking the viscosity: if the fluid is too thick to drip off the end of the dipstick, it is too viscous to function properly. Trying to run your system in that condition will seriously damage it. This increase in viscosity is also why it is important to give your hydraulic equipment a chance to warm up before use. Start up the equipment and let it idle in order to warm up the hydraulic system and the fluids that it depends on before you put the equipment to work.

In general, it is important to make sure the fluids used in the system are appropriate for the expected temperatures, taking into account atmospheric pressure if high altitude conditions are involved. Manufacturer guidance should be sought if there is any question as to what type of fluids are appropriate in cold temperatures.

When hydraulic fluids and lubricants are exposed to high temperatures for extended periods of time, the fluids will begin to experience permanent deterioration and a severe reduction in viscosity (i.e., the fluid will be much thinner and less viscous). The deterioration of hydraulic fluid leads to oxidation (in fact, the oxidation rate itself significantly increases with temperature) and the formation of problematic sludge. At the same time, the fluid will experience chemical reactions between degrading additives, all of which seriously compromise the performance of the fluid and the hydraulic system as a whole.

The reduced viscosity can render lubricants and hydraulic oil useless when it comes to protecting components through reducing friction, preventing abrasive damage, and minimizing the speed of wear. A change in viscosity also affects the behavior of the hydraulic fluid itself, negatively impacting the performance of the hydraulic system as a whole. Depending on a combination of pressure and temperature, some fluids may actually reach a vapor state — which will obviously lead to damaged systems and components.

While the use of a hydraulic fluid that includes a VI (Viscosity Index) improving additive may alleviate the problem of reduced viscosity in high temperatures, it is vital to remember that extended exposure to high temperatures can cause this very additive to breakdown — meaning that VI improving additives are not an easy solution to the problem. Even more interesting is the fact that extended high-temperature operation can deplete other critical additives, including foam depressants, rust inhibitors, antiwear ingredients, and antioxidants.

As fluid deterioration continues and key additives such as rust inhibitors and antiwear ingredients begin to deplete, then the components within the system (hydraulic motors, pumps, valves) will begin to experience accelerated wear. System performance and efficiency continue to drop and the system will begin generating its own heat. The result is a lethal cycle of damage to your hydraulic system as a whole and the components within. If the accelerated wear is allowed to continue unhindered, then bits of surface metal may begin to wear away, forming flakes and tiny particles that will contaminate the hydraulic fluid and exacerbate the wear.

High temperatures can result from extreme ambient temperature but are more likely to be the result of heat generation within the hydraulic system. Because heat can be so damaging to a hydraulic system, it is important to track down the source of heat generation. Heat generation commonly results from fluid flowing from an area of high pressure to an area of low pressure without any output of mechanical work. One source of such a loss of pressure is friction. High friction in the system will generate heat, and sources can include the following:

Other heat sources can include the compression of aerated fluids, which occurs when the hydraulic fluid is contaminated with air. The compression of aerated fluid within a pump can quickly lead to temperatures around 2000°F.

In some cases, the heat may not be generated by the system itself. If the hydraulic system is operating near a heat source, that could cause problems for the hydraulic system. A lack of proper ventilation can also result in elevated temperatures.

Temperature extremes will affect the performance of your hydraulic system and result in serious (and expensive) damage if nothing is done to either address the temperature issues or protect the system from the effects of the temperature. This is true whether it is a small snowplow operating during extremely cold ambient conditions or a hydraulic system in a manufacturing plant that is generating enough heat to raise its operating temperature beyond recommended limits. The most immediate effect of temperature involves the viscosity of the fluid: cold temperatures will increase fluid viscosity, making it thicker; high temperatures, on the other hand, will decrease the viscosity of the fluid. Such changes in viscosity can quickly lead to permanent damage to the hydraulic system and its components.

Changes in performance can be due to operating temperatures, and addressing those issues for high temperature situations involves some investigative work to determine the source and cause of the heat generation.

As one of our many services, MAC Hydraulics offers on-site maintenance of hydraulic systems and equipment with fully equipped service vehicles and skilled technicians who only work on hydraulics. Our experienced technicians will perform fluid analysis, inspect and replace hydraulic hoses, check fluid levels, replace filters, and perform other necessary maintenance tasks. If you have problems — including temperature issues — any time, day or night, MAC Hydraulics will send out one of our technicians to inspect, troubleshoot, and address your hydraulic problems using state-of-the-art equipment they have been trained to use. We even offer machining and welding services as needed. Whether you have a small hydraulic system on mobile equipment or a massive, complex hydraulic system that is the heart of your plant, contact us today to see how our technicians can help you develop the ideal maintenance plan for your hydraulic machinery!

Hydraulic pumps are essential components in countless different types of applications. In many cases, they’re expected to run around the clock, and any downtime can grind operations to a halt.

Hydraulic pump failure has a number of different internal and external causes, and understanding what those are can help prevent issues in the future. Poor maintenance, extreme operating conditions, and problems with other components can all contribute to failure and can all be carefully planned for and monitored to prevent any issues.

Ideally, you’ll discover that there’s an issue with the pump before a complete failure. Identifying any problems earlier will give you more time to plan a response instead of scrambling when operations shut down unexpectedly. Minor fixes can even be incorporated into your

Loud noises are going to be one of the most serious indicators of hydraulic pump failure. While your pumps will be making noise during regular operation, various faults can cause a loud knocking or banging. If you start to hear these noises from your pump, failure is likely right around the corner. Consider it your pump crying out for help.

Temperature is another key factor to watch for hydraulic pumps. Most hydraulic systems recommend operating at no more than 180 degrees Fahrenheit or 82 degrees Celsius, and temperatures climbing higher than that are a clear indication that something is wrong.

Finally, the clearest sign that something is wrong is going to be the system performance itself. If your system is operating slowly, it’s likely due to internal leakage or other issues.

Continuing to use the system with a partially damaged pump will only speed up the complete failure of the hydraulic pump, so it’s best to address these issues as soon as you notice any signs.

Many different factors can lead to hydraulic pump failure. No matter what the specific cause, it’s important to remember that pump components likely haven’t broken for no reason at all. Pump failure is a sign that something must be wrong somewhere in the system, with the effects ultimately leading to the failure of the pump.

Cavitation is a likely cause of loud banging noises coming from the pump. Dissolved gasses within the oil can react to pressure differences by coming out of the oil and then being collapsed by the high pressure.

Aeration can have similar effects. This issue occurs when external air enters the system through leaks, loose connections, or other problem areas. It generally creates a much more mild knocking but is still causing damage that eventually leads to hydraulic pump failure.

Water in the oil can be another major issue, especially when it is allowed to freeze. This problem can be much more difficult to identify as it won’t be making identifiable noises.

The look of the hydraulic oil itself can give an indication of water contamination by appearing hazier and less clear than usual. Water contamination will wear down hydraulic components and can cause oxidation over time as well.

Significant overheating can lead to oxidation of the hydraulic fluid, which causes the fluid to become thicker. This thickening can limit flow through the system, further reducing heat dissipation and potentially causing even more severe overheating.

Low temperatures can also cause problems. The hydraulic fluid can only effectively flow once it approaches operating temperatures. Pump failure can be caused by increasing the load before the operating temperature is met, which is more common with lower ambient temperatures.

Many different mistakes can lead to premature or even immediate hydraulic pump failure. A faulty installation could result in instantaneous and catastrophic damage to the system or gradual wear that isn’t discovered for years. Poorly fitted pipes and other pump components could contribute to leaks.

An incorrect combination of different parts can cause hydraulic pump failure as well. A motor might have excessive drive speed for a pump, or various types of control equipment can be incompatible. In any case, these issues can lead to increased wear or even immediate failure.

Failing to implement effective maintenance will also lead to premature failure. If the proper maintenance schedule isn’t followed, excessive wear can develop. This risk is true for both the pump and other system components that can affect the pump if not properly maintained.

Even if a hydraulic pump is replaced or repaired, the issue is likely to occur again if the root cause isn’t identified and resolved. This diagnostic could mean evaluating the entire system to find out just what went wrong. There could be other components that allow for fluid leaks or air and water to enter the system.

To prevent future hydraulic pump failure, you should ensure that the system follows all relevant specifications. Operating outside of these specifications could cause damage to the pump and other components that eventually lead to hydraulic pump failure.

After a pump failure, a professional inspection of the entire system may be in order. Avoiding this precaution could lead to another failure shortly or even more excessive damage to your hydraulic systems.

Many hydraulic components are relatively quick and inexpensive replacements, and avoiding necessary repairs can only lead to serious issues down the line.

The team at MAC Hydraulics can provide all of the services you need for your hydraulic system, including professional troubleshooting. We offer replacement hydraulic pumps, repair pumps, and cover maintenance to prevent unexpected hydraulic pump failure.

For fast and effective troubleshooting, you can reach out to us as soon as you notice issues like increased noise, oil leaks, loss of power, limited flow, or overheating. Our team will determine the root cause of the problems you’re experiencing with your pump to ensure that they won’t happen again.

That also includes effective resealing to help you get the most out of your existing components, instead of having to replace them before their time. Our experienced team can go over your options and find the best solution for your hydraulic systems today.

You rely on your hydraulic systems every day and can’t afford to let hydraulic pump failure grind operations to a halt. Whether the issue is air or water contamination, overheating, over-pressurization, human error, or anything else, the end result will be the same when your pump quits.

Every component within a hydraulic setup will affect the overall system. Hydraulic pump failures can indicate further issues with other parts of the system. Looking into exactly what the real cause is can help prevent additional failures in the future.

Whenever your system suffers from pump failure, it’s best to go with trusted professionals for the replacement or repair you need to get running again. An experienced team can ensure that you have the right pump for your system and that the installation is carried out safely and reliably.

Heat is a form of energy associated with the motion of atoms or molecules in solids and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection and through empty space by radiation.

For our use in hydraulic applications, we need to translate the definition above into a more workable statement that will help us better understand the physics behind this phenomenon called heat. Something like “Anytime fluid flows from a high pressure to a lower pressure, without producing mechanical work output, heat is generated.”

The use of flow controls, proportional, reducing, relief, reducing/relieving, counterbalance and servo valves all create a pressure drop in order to do their job.

Incorrect sizing of fluid conductors can cause the generation of heat. For example, with ½ inch OD pipe, a flow rate of 10 GPM generates heat at the rate of about 25 BTU/FT-HR. Doubling the flow rate to 20 GPM increases heat generation 8 times to about 200 BTU/FT-HR. Here are some rules of thumb when sizing hydraulic conductor velocities:

As pumps wear, the internal leakage or “slippage” increases. On fixed displacement pumps this leakage flows from the high-pressure outlet back through the pump to the low-pressure inlet. In a pressure compensated pump this flow is forced out through the case drain. As this occurs fluid is taken from a high pressure to a low pressure without doing any mechanical work thereby creating heat.

Pulsating accumulators may develop high pressures on the gas side. This heat can transmit back into the oil raising the temperature and creating a hot spot in your hydraulic system.

When a load is lifted hydraulically, potential energy is stored in the load. Release of the load usually involves non-regenerative throttling, which generates heat.

Heat has many detrimental effects on the hydraulic system components. But the most detrimental effect of heat is the breakdown of the oil. Oil temperatures should be maintained at 120°F for optimum performance, and should never be allowed to exceed 150°F. At high temperatures, oxidation of the oil is accelerated. This oxidation shortens the fluid’s useful life by producing acids and sludge, which corrode metal parts. These acids and sludge clog valve orifices and cause rapid deterioration of moving components. The chemical properties of many hydraulic fluids can change dramatically by repeated heating/cooling cycles to extreme temperatures. This change or breakdown of the hydraulic media can be extremely detrimental to hydraulic components, especially pumping equipment. Another effect of heat is the lowering of the oil’s viscosity and its ability to lubricate the moving parts of the pump and related hydraulic equipment effectively.

A = the surface area of the reservoir in sq. ft. The surface area of the bottom of the reservoir can only be used in the calculations if the tank sits 6.0 inches off of the ground.

This can be accomplished by adding a solenoid vented relief valve on fixed displacement pumps and a solenoid vented control on pressure compensated pumps. This will remove the high-pressure component of the definition above.

Heat exchanges can be used to remove the excess heat in a hydraulic system. The implementation of heat exchangers has many variables that need to be taken into account. Rules of thumb when sizing a heat exchanger are as follows:

Multiply the input horsepower (motor hp) by the percentage listed above that best describes the system parameters. For example, if your system is a simple circuit with fluid motors and has an electrical motor input horsepower of 30hp: 30hp X 0.31 = 9.3hp

The tank needs to dissipate at least 9.3 horsepower or the system will overheat. Another rule to keep in mind is if your system pressure is above 1000 PSI and your tank is sized for 3 times or less pump output you WILL need a heat exchanger.

There are many more aspects of thermal characteristics within a hydraulic system than this paper was meant to cover. With this information, you should be able to make educated decisions when working with an existing system or new design in order to combat heat generation. With this information you should also feel comfortable calling a specialist to discuss ways to minimize the heat you may experience in your system. When in doubt, consult your local fluid power professional

Note: “Tech Tips” offered by Flodraulic Group or its companies are presented as a convenience to those who may wish to use them and are not presented as an alternative to formal fluid power education or professional system design assistance.

When a hydraulic system fails, finding the source of the problem can be a challenge. Though hydraulic systems primarily consist of a sump, motor, pump, valves, actuators and hydraulic fluid, any of these parts could be the source of failure. That"s not to mention the additional potential for failure through human error and faulty mainten