Protecting refuse vehiclesā hydraulic systems requires an āall hands on deckā approach that necessitates a commitment and buy-in from top management, fleet maintenance and route drivers.
Contamination of a refuse vehicleās hydraulic system oil is a significant issue that can lead to multiple problemsārobbing it of performance, reliability and productivity.
The effects of contamination comprise a laundry list that includes some of haulersā most pressing issues: loss of vehicle efficiency, fine controls and position holding, internal leakage, sticky and erratic controls, and rust and corrosion. It is not a pretty picture.
Once a contaminant is introduced, it flows through the entire hydraulic system from the pumps, through the lines and all the way back to the reservoir. āContamination found in hydraulic oil acts like little pieces of sandpaper. As it circulates, it wears the inside linings of the hydraulic lines as well as other components,ā said Dave Spadell, Director of Refuse Sales for Mailhot Industries USA. The problems can quickly escalate as contaminants circulate throughout the system. āAs the contaminated fluid gets inside the hydraulic pump, it wears down the internal components leading to catastrophic failure,ā explained Spadell. āNow, you not only have ingested contaminants suspended in the oil but youāve added metal particles.ā
If the particles are large enough, the orifices inside a valve can get clogged, blocking oil flow, and that begins to shut down the function of the vehicleās entire system. āItās analogous to arterial disease within your vehicleās hydraulic system. These particles continue to build up until you get a catastrophic failure,ā said Spadell.
Hydraulic system failure can result in the need for pump, valve, line and cylinder replacementāan expensive proposition. Now the hauler is saddled with cleanup costs, labor costs and productivity loss caused by vehicle downtime. āIf you have a leak anywhere on your truck, you have a means where contamination can get in, and that spells trouble,ā states Spadell.
Where Does Contamination Come From?
Like bacteria and viruses attacking your own body during the flu and cold season, contamination of your refuse vehicleās hydraulic system can come from many sources. One of the most overlooked is the built-in manufacturing scraps and residue inside new but dirty components. Ingression of particles through leaking seals, worn fittings and worn breathers are other important sources. Repairs and service completed under less than ideal conditions, or inadequate cleaning during reassembly of lines and components, is yet another. Letās look at a few of these in more detail.
A Primary Cause: Cylinder Ingestion
A primary route for the introduction of contamination into a hydraulic system involves the packer cylinders. āWe estimate that about three-quarters of ingested contamination gets in through the packer cylinders,ā explained Spadell. āIf the driver dumps a can behind the blade, there is now trash sitting on the cylinders, the primary point of contamination ingestion.ā
As the cylinders cycle, the hydraulic system temperature is typically operating between 150 to 160 degrees. Inside the cylinders are five to seven gallons of hydraulic oil (depending on the type and size of cylinder). Anything sitting on that cylinder will start to cook and bake onto the surface. Then, as the cylinders operate, this ābaked onā material can get sucked into the hydraulic system.
If the particles are small enough to get past the wiper sealāand get lodged inside of the body of the cylinderāthe end result is a cylinder that cannot perform to its specifications. āThe cylinder may be rated to compact 10,000 pounds, but because the hydraulic pressure is partially bypassing the piston due to internal cylinder body scoring, now you may only be able to compact 7,500 pounds and no longer be able to perform to specifications.ā The bottom line is a huge drain on productivity.
āWhen the fluid bypasses the piston due to internal scoring, you create heat within the system and, as temperatures rise, the performance of the hydraulic fluid drops,ā explained Spadell. āPlus, any water or compressible liquid that finds its way inside your hydraulic fluid is under extreme pressure. As this liquid is compressed by the hydraulic pump, it explodes, resulting in little pieces of metal that are now introduced to the system.ā
Self-Inflicted Causes
Other ways that hydraulic system contamination typically occurs may be of the self-inflicted variety. āLetās say a truck goes into the shop and the technician notices a hydraulic leak and needs to refill the system with oil,ā said Spadell. āIf the technician doesnāt carefully clean around the inlet port of the hydraulic tank, some of that dirt can wind up inside and is introduced into the system.ā
Another common cause of contamination happens during a hydraulic line repair in the field. āA technician in the shop cuts a new hydraulic line and installs the fittings as quickly as possible to help get the truck back into service,ā said Spadell. āDebris and dust created while making the hose is now inside the hose. The technician has just contaminated their own vehicle.ā
The effect on productivity is significant, but the cleanup costs are equally staggering. āDepending on where the downed vehicle is located, your technician could be an hour away,ā said Spadell. āBy the time the technician arrives with help the vehicle has been sitting and not picking up any trash. And you probably just put 10 gallons of hydraulic oil on the ground that has to be cleaned up.ā
Strategies to Minimize Contamination
There are a number of strategies to employ in order to minimize the risk of contamination. First and foremost, prevent leaks from occurring in the first place. Cylinders equipped with shaver technologies, which were developed and tested to address contamination are the first line of defense. Fleet managers need to take precautions to ensure that the hydraulic cylinders are kept in good condition through preventive maintenance. Minimize the amount of trash and debris permitted to come in contact with the hydraulic cylinders.
From a maintenance standpoint, Spadell stresses that haulers should fabricate new hydraulic lines in a sterile environment, and be careful when topping off or refilling trucks. āClean the top of the truckās oil reservoir before you stick a hose in there, and the same goes for the drums of oil you are using to fill the trucks,ā he notes.Ģż āWhen swapping out oil barrels from one to another, carefully and thoroughly clean the top before opening and using.ā
External Filtration Prolongs Oil Life
External filtration treatments should be done on a regular schedule. Run trucks through filtration at a baseline minimum of at least every six months to cleanse its systems. The objective is to lower your ISO counts, which measure the amount of contaminants in hydraulic oil. By lowering the ISO cleanliness codes, you significantly extend the life of your hydraulic oil. āThe typical truck has 50 gallons of hydraulic oil, and the cost is up to nine dollars per gallon,ā said Bob White of Schroeder Industries. āIf you can extend the oil life, the savings are significant. Thatās where the value proposition is.ā
Depending on the type of filter cart, a technician can attach it to the vehicleās quick disconnects and allow the cart to filter the hydraulic system while completing a brake job or other maintenance or repair procedure. Some haulers choose carts that can run at night and shut off once the job is completed. āSome carts will filter down to your preset ISO count setting, and by going down one ISO count you halve the amount of contamination,ā explained White. āOnce it hits that targeted ISO count, the filter cart will automatically shut itself down.ā
High performance filter carts are now available that allow the technician and fleet management to track the service history for each and every truck in a fleet. āWhat makes a filter cart unique is that it has an onboard particle counter that interfaces with a full functioning PC,ā says White. āIt is easy to operate and allows your maintenance team to track the oil cleanliness for each and every truck in a fleet.ā The data collected enables a fleet manager to analyze where the ISO counts are after a certain amount of time and extend the drain interval based on oil cleanliness rather than a preset schedule.
Some Big Numbers
By using a state-of-the-art external filtration cart, it is estimated that haulers can double the life of hydraulic oil. At $8.00 or $9.00 per gallon, and 50 gallons per truck, that number is significant.Ģż āI know a fleet manager that was dumping their hydraulic oil every six months,ā said Spadell. āI did the math for him. With 42 trucks in his fleet, he was going through $70,000 per year in hydraulic oil. By moving to a high performing filtration cart, he was able to save $35,000 per year.ā
White added, āI know of trucks that are running two to three years on the same oil. If you are able to do that over an entire fleet, the ROI is significantābut you have to have support and use the tools at your disposal.ā
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Harsh Environment Requires Diligence ĢżĢżĢżĢżĢżĢżĢż
The refuse hauling industry is a harsh environment for hydraulics because vehicles are constantly under attack by contaminants. Regular maintenance and proper filtration are very important but operator behavior is equally important. āYou need to make sure drivers are clearing out behind the blade every day, but in reality very few do,ā said Spadell. āAnd drivers need to avoid dumping behind the blade as much as possible.ā
Protecting refuse vehiclesā hydraulic systems requires an āall hands on deckāapproach that necessitates a commitment and buy-in from top management, fleet maintenance and route drivers. When refuse vehicles are maintained using best industry practicesāadoption of a comprehensive maintenance program, application of innovative technologies and all-inclusive trainingāthe life of the hydraulic system and its oil can double. The benefits to an organizationās bottom lineāand the environmentāare substantial, and the ROI is a gamechanger.
McNeilus Companies is an industry-leading manufacturer of refuse truck bodies. McNeilus produces a complete line of rear load, front load and automated side load units to augment any refuse collection fleet. Each product line offers multiple models to fit customersā specific needs. Through its Next Generation Initiatives program, McNeilus designs, installs and services CNG solutions for heavy-duty fleets of all types, all supported by a comprehensive, factory direct sales and service network. For more information, visit www.mcneiluscompanies.com.
Participants
David Spadell is director of refuse sales for Mailhot Industries USA (Hudson, NH), manufacturer of the Excalibre cylinder product line. Mailhot focuses on vehicles that perform in harsh environments, including refuse hauling, construction, mining and snow removal. David can be reached at 603-880-9380 or via e-mail at [email protected].
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Bob White is New Business Development Manager, for Schroeder Industries (Leetsdale, PA), an ISO 9001: 2008 certified company that designs, manufactures and markets filtration products for the hydraulic and lubrication, filter systems, process and fuel industries. For more information call (724) 318-1100 or e-mail [email protected].
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Sidebar
Pride Disposal: Comprehensive Program Pays Dividends
Pride Disposal Company (a family owned solid waste hauler headquartered in Sherwood, OR) runs a well-rounded fleet with both diesel and CNG powered trucksāincluding five semi- trucks, six roll-offs, seven front loaders (five McNeilus) and 18 McNeilus AutoReach Automated Side Loaders. āWe run with McNeilus because the support has been great for both service and parts,ā said Pride Disposal Fleet Manager, Bill Woody. āMcNeilus is always working to better their products and training programs to help our company be more efficient and productive.ā
Pride has fully implemented a comprehensive preventative maintenance program to extend the life of its trucks and components. ĢżāPrior to launching our program, our trucksā hydraulic systems experienced a two to four year life expectancy, depending on the component,ā said Woody. āNow, we are doubling that number.ā
The majority of Prideās vehicles are seen six times per year for regular maintenance, with oil samples done at each service event to help Woodyās team make repair decisions and schedule trucks for down time. āThe oil samples help us determine if we are getting contamination in our systems from metals or outside foreign material,ā said Woody. āThis helps us to know if we can simply clean our hydraulic system or if we need to replace the hydraulic oil and filters and clean out the tank.ā
Another big reason cited for the extra longevity is Prideās adoption of Excalibre hydraulic cylinders from McNeilus Street Smart Parts. āThe Excalibre cylinder is nothing less than phenomenal,ā said Woody. āIn the last year and a half, we replaced two sets of Excalibre cylindersāone had been in service for seven full years and the other for eight years in two of our McNeilus Front loaders,ā said Woody. āThatās an amazing return on investment. It saves on cylinders and labor.ā
āOur bottom line on why we like the Excalibre cylinder is that you never know what youāre going to get in garbage,ā said Woody. āIf plastic or paint lands on the cylinder rod, those are removed by the scraper and not ingested into the system. Plus, if you get a ding or dent in a rod, the Excalibre will automatically trim those off before they can get to the seal and cause problems. Quite simply, itās a superior design and superior engineering. Theyāve lasted twice as long as any other weāve used. If the cost is 20 percent more but your are getting twice the life, thatās a no-brainer.ā
