Skid Steer Attachments Drive the Decision
5th Jan 2021
Rarely does a skid steer owner use only a bucket. The auxiliary hydraulic capabilities of a skid steer are one of the features that make it extremely versatile, and having a good understanding of the output you will need is important when you spec a machine. How much power is too much power, and how much power do your attachments need? In this article, we’ll look at common hydraulic systems and how each matches up to attachment demand. Just working with a bucket and pallet forks? No problem. Running snow throwers and wood chippers? You’re going to need a higher flow.
Attachments
Drive the Decision
A skid steer’s auxiliary hydraulic system provides the hydraulic flow that
drives the machine’s attachments. The key to remember is that not all
attachments have the same hydraulic flow requirement. The most common system is
the standard-flow auxiliary hydraulics package. Although flow rates differ by
manufacturer and skid steer model, the flow rate of a standard-flow system
ranges from 17.5 to 24.2 gallons per minute (gpm). Standard-flow auxiliary
hydraulics are included on all skid steers from the factory and operate on the
same pressure that the machine’s main hydraulics operate on, which is
approximately 3,000 pounds per square inch (psi). A standard-flow system powers
many of the most common hydraulic attachments on the market, such as 4-in-1
buckets, hydraulic hammers, augers, trenchers and grapples.
A high-flow auxiliary hydraulics system is a second option that further increases a skid steer’s versatility and productivity. As with standard flow, it operates on the same pressures (approximately 3,000 psi) the main hydraulic circuits operate on. The flow rate, however, ranges from 30.7 to 37.6 gpm. A high-flow system can be factory-installed as an option or installed later in the field. It powers production-type attachments that require a high-flow rate to perform as specified. Examples include cold planers, many snowblowers, rock saws, small mulchers and chipper/shredders.
When even more
hydraulic power is required, an enhanced high-flow auxiliary hydraulics package
is available. This high-performance option has flow rates that are similar to a
skid steer with a high-flow package, yet it operates up to 4,000 psi. Examples
of attachments that require an enhanced high-flow system include larger cold
planers, larger mulchers used to clear brush and small trees and large rock
saws you might find in an aggregates operation.
Also available is a secondary auxiliary hydraulics system for applications that
require multiple hydraulic movements simultaneously. This would include the
side-shift function on a cold planer or stump grinder, snowblower for direction
change on the chute or a tree spade with down riggers.
Understanding Demands and
Limits
A common misconception is that a standard-flow system can adequately run
high-flow attachments. Powering high-flow attachments with a standard-flow skid
steer will lead to inefficient operation. In addition to realizing
lower-than-expected results, it can also damage the attachment or skid steer.
There’s no need to invest extra money in a high- or enhanced-flow system if
your attachments only call for standard hydraulic flow.
When it comes to an enhanced high-flow auxiliary hydraulics package, it’s
important to know the system is designed for extreme situations where the
operators are truly pushing the limits. The enhanced high-flow package is only
available on larger skid steers with the horsepower available to ensure proper
operation of the attachment.
Another common misconception and mistake in operation is that it’s best to run
the attachment “wide open” and use all of the flow and pressure available. This
is incorrect, and many attachments come labeled with optimal parameters for
operation. Most large attachments are equipped with a pressure gauge to help
operators run the attachment well within the recommended pressure guidelines
for optimum cooling and performance. A good suggestion is to keep the
attachment at 5 to 10 percent off of its maximum pressure to get optimum cooling
and performance at the same time. Exceeding these ratings can lead to damage
and unnecessary stresses on the machine.
Maintenance Is Universal
The maintenance involved in auxiliary hydraulic systems is essentially
universal. As with any hydraulically operated machine, it’s important to
maintain the proper hydraulic fluid level as specified in the owner’s manual.
To ensure safety, check the level with the loader arms in the down position.
This also ensures an accurate reading. Loader arms in the up position will draw
fluid from the hydraulic fluid tank, giving the false impression that fluid is
low.
The general guideline is to change hydraulic oil every 1,000 hours; filters
should be changed every 500 hours. Always follow the recommendations in the owner’s
manual. Equally critical is the need to minimize the potential for
contamination, whether it’s dirt, particulates or water. Check connection
points to ensure they’re tight, and keep them clean. Contaminated hydraulic
fluid decreases the life of the hydraulic pump and system and can lead to more
serious issues if not regularly changed out.
Viscosity is the single most important factor when selecting a hydraulic fluid
to use in the skid steer. Follow the manufacturer’s recommendations to select
the viscosity grade to meet the machine’s operating requirements and climate
the machine will be operating in. Doing otherwise will result in poor
performance or unnecessary damage. The wrong oil in a cold climate could lead
to sluggish performance and damage to hydraulic components, while the wrong oil
in a warmer climate may not provide the needed viscosity and may actually cause
heat buildup in the unit.
Making It Work for the
Business
One of the most common mistakes contractors make is buying a skid steer without
enough hydraulic power. Having high flow and not needing it is better than not
having high flow and needing it. If you think you may be expanding your
business — such as a landscaper who may be considering a move into snow removal
— consider the high-flow system.
With literally hundreds of attachments available and more introduced each year,
it’s a given that the versatility of skid steers will only continue to grow. By
outfitting them with the right auxiliary hydraulic systems, skid steer owners
are able to capitalize on all the machines have to offer, achieve a favorable
return on investment, and ultimately, add to the bottom line of their business
in the process.