Hydraulics are one of a tree care pro’s best friends, powering tools that lift and move heavy objects and debris, or doing specialty work like cutting, digging or grinding. The growing proliferation of tool carriers and hydraulic tools has expanded the capability of almost every arborist operation and, by transferring tasks from the human to the machine, improved safety and prolonged careers.

But, and it’s a big but, one has to watch what one is doing so as not to hurt the hydraulic tool, the machine or the operators and crews using them. It’s a matter of paying attention – or paying the price.

Taken for granted
Those we spoke with for this article agree that all too often, owners or operators will use the equipment, then just put it away at the end of the day. Next day, they haul it off to the next job, firing up these precious fleet pieces with little to no inspection. They argue that the operator is so busy, or the operator has so much confidence in the technology, that they take hydraulics for granted. Bad move.

Over time, failure to be fastidious about maintenance and repair will cost you – that’s pretty much guaranteed. For example, failure to change a simple $25 hydraulic filter can damage or destroy a hydraulic tool or tool carrier, right up to a large articulated loader. The cost may not always be in money or equipment; instead, you may pay the price on the human side.

Dangers to operators and crew
Frank Dobbins is involved in the purchase and maintenance of equipment for Ryan Lawn and Tree Care, a 25-year TCIA member company with six branches in four states: Kansas, Missouri, Nebraska and Oklahoma. Dobbins makes an eye-opening point, stating, “A simple pinhole leak on the high-pressure side of the hydraulic system can cut you open like a razor.” It happens, he says.

With a half-century of experience as a mechanic – his dad started him on engine rebuilding at the age of 10 – Dobbins starts with the basics, explaining that most systems have a high and low hydraulic-fluid flow setting. He stresses that, “The high and low flow is a big thing,” allowing the machine operator to correctly apply the volume and pressure of hydraulic fluid for the job. Capability and efficiency of a hydraulic machine, small or large, is a matter of the amount of fluid flow and the pressure at which it flows. Think of a standard garden hose; fluid and pressure determine the outflow, depending on the needs of the gardener.

According to Dobbins, for the health and lifespan of the unit, “It’s important to use the correct setting on the pressure side. Operators might be tempted to hook up a log grapple on the high-pressure side, thinking one of two things: that that will get the job done faster running at higher pressure, or that the system is running slowly because of poor maintenance or mechanical issues.”

Dobbins says that that may work for a while, but that odds are the increased pressure will cause premature wear or, more seriously, operators will think they have outwitted the technology. He notes that the odds are that a slow or sluggish machine may not get reported for maintenance or repair, which is likely to result in major to catastrophic repairs.

“I teach this to all my crews,” Dobbins says, “to always change back from the high to slow side when they are done using a high-pressure attachment. You need the high side generally for one thing, powering a tool with an internal hydraulic motor, such as a saw, trencher, mower deck – anything designed to run only on the high-pressure side. Anything without a motor and just a hydraulic cylinder runs on the low-
pressure side. Period. Every loader, low side only,” he reinforces.

“It’s very important to follow procedure on the machine and the attachments,” Dobbins adds. Take the case of a loader that’s been stretched to its limit over time. Dobbins says damage can cause a slow leak, which can affect the machine’s three pumps, since they share the same hydraulic tank. “Damage to one can damage them all,” he maintains, and that can run up to $25,000 to $35,000 to replace all three if they are contaminated from overwork or neglect. “That can be up to half the cost of a new machine,” he warns.

All of that can come from not changing fluid or filters in a timely fashion, or unnecessarily overworking the machine.

Mistakes happen
“It has happened here,” Dobbins recalls. “People make mistakes. We recognize that and try to educate them. Second time may come out of their pocket.”

The key to safe, efficient and long-lasting use of hydraulic machines and attachments is, according to Dobbins, “routine maintenance on attachments and regular visual inspections, looking especially for seepage, which may signal the need to change a hydraulic cylinder.

“This applies to things like a leak on a manicured lawn,” he states. “If hydraulic oil hits the lawn, it’s dead and has to be dug out and reseeded or have new sod, which can be expensive.

“Routine maintenance can save a lot of money. I try to check hydraulics at least once a month,” Dobbins reports, “because even a small drip can turn into a costly leak.”

He says to check everything and be thorough. “There are some hydraulic hoses with protective sleeves, and sometimes you have to take the sleeves off to do a complete inspection.” And he goes to the trouble of ensuring that not only are fittings tight, but not too tight, especially where hoses fit into an attachment. He explains that if the fittings are over tightened, they may crush the O-rings, which can damage the rubber rings and allow broken pieces to enter the hydraulic environment, likely leading to fluid breakdown or attachment/equipment damage caused by debris.

Dobbins is cautious. “Another routine maintenance practice of mine is to change the hydraulic oil filters every 200 hours, even though the book says 400.” He argues that a small amount of dirt or debris can slow flow to an attachment, making it work harder and leading to failure or premature wear-out. “The cost can be thousands, just from a dirty filter,” he warns.

“I’m a believer in flushing the tanks and lines every two years,” he adds, explaining that, over time, not only is there a chance of contamination, but the heat that builds up even in regular use will break down oil viscosity. It gets thinner and thinner, making the hydraulic system work harder and leading to the possibility of burned-out seals as the heat rises. “That’s another reason I’m always looking for drips and seepage.”

A last-minute warning from Dobbins. “Do not mix different kinds of hydraulic oil to top off the tank. Use exactly what’s in there. Take time to get the right stuff,” he cautions.

“It’s not rocket science. Pay attention to your hoses, fittings and attachments,” he concludes.

Up a notch
Taking hydraulics up a notch is Rick Cooney, president of Westminster Hydraulics, a 12-year TCIA corporate member company headquartered in Taneytown, Maryland. Since 1979, Westminster Hydraulics has built its reputation in many industries by manufacturing articulating boom trucks, along with other equipment such as custom truck bodies and larger attachment tools for the tree care industry, such as grapple saws.

Cooney agrees that regular inspections are key to safe, long-lived hydraulic equipment, regardless of its size and application.

He says that on the crane side of the business, along with grapple attachments, “We do annual inspections (for customers) a lot. Crane inspections are supposed to get done annually,” he says, “but in tree care it’s twice a year because of the shock load.”

Cooney reports the close inspection is “from tank to boom tip – hydraulic lines, hoses, fasteners.” He says his team can show an operator what to look for, such as where a bolt, if it backs off, can break a cross-check valve, which will dramatically affect the safety and use of the system.

“We go top to bottom, front to back, checking all fittings, hoses, pipes and control valves and looking for the little things, like burrs that can cause abrasions that can wear through a hose. When we see burrs, they fail the inspection if the hose protective covering is worn off. It’s a red flag, because you cannot know when the hose will blow.” (For an example of this, see Michael Roche’s anecdote in “Pretty Simple – PPE Works!” by Don Staruk, TCI Magazine, April 2025)

Cooney says it’s not only burrs, but similar wear caused by the elements – rain and salt – which will deteriorate metal wrap and cause a failure at some point. “It’s a given,” he maintains.

During an inspection, he says, “We also have to actually get into the equipment.” In the case of a grapple, for example, Cooney says there are parts that come in contact with the tree, pulling at hoses, pulling them out of their retaining bracket or stretching them. “A lot of times workers do not take the time to look. Even with spiral (protective) wrap,” he says, “we need to take off the spiral wrap to do a proper inspection.

“We check flow and pressures and inspect the hydraulic motor on the grapple saw,” he continues.

Not a failsafe
“We also inspect metal safety guards, which can get bent and pulled off during grapple-saw operation,” Cooney reports. The reason for that, he says, is that as the boom rises and falls, it can pull branches past the guard and into the non-moving steel hydraulic pipes, perhaps bending or damaging them.

According to Cooney, with respect to truck-mounted hydraulic pumps, correct pressure is critical. “If the pressure is down, it can be boosted by the operator,” he notes, “But once the pump wears down to where it can no longer boost to the correct operating pressure, the pump has to come out.”

For a quick rule of thumb, Cooney adds, “Pressure and return filters need regular replacement at least annually. Check for debris in the tank. It happens when someone opens the tank without clearing completely around the cap, then debris goes into the tank and to the pump, which wears out.

“Hydraulic oil that looks milky or like chocolate milk can get moisture into components, like a control valve, and rust them. Immediately drain the oil and clean the tank,” he says.

Cooney also advises to look for debris on wire-mesh filters, on the pressure and return filters and on the bottom of the filter cup, and to inspect the debris for things like bits of metal parts and bits of O-rings. “Find out what’s causing that before the machine stops working or the grapple saw is not holding,” he adds.

Conclusion
Concluding with a reminder, Cooney says, “Whatever tool you’re attaching has to coincide with pressure and flow of the truck or carrier. Work with your dealer or someone who understands hydraulic systems.” He says it is not likely a typical user has the tools and skills to match a tool to a tool carrier, especially if problems arise. “When you buy from a manufacturer, there is a manual specific to that piece of equipment, including outlining required flows and pressures.”

As stated previously, failing to do that correctly can result in situations of over or under pressure that can be dangerous, or even deadly, to humans and machines.

Pay attention, or pay the price.

Rick Howland is a veteran newspaper reporter and editor, former national magazine owner and editor and retired international consultant in public relations, advertising, merchandising and training. He lives in the upper Hudson River Valley of New York.