Equipment Type

Component Health Check

Most fleet professionals recognize the importance of scheduled preventive maintenance (PM). Condition monitoring of components could well be considered a more sophisticated attack on wear and tear. The spear point backing up the line of defense is a combination of technology and analytical data.

August 01, 2011

Reprinted with the permission of Equipment Manager magazine, the magazine of AEMP.

John E. Dolce, fleet specialist for the New Jersey-based architectural and engineering firm, Wendel, Inc., came up with some interesting numbers. He says a single mobile construction vehicle consists of 15,000 parts and about 300 of them, as they age, need to be monitored for erosion of quality. These components, including the engine, have life cycles of their own and ignoring their condition can lead to a world of hurt.

Components that should be monitored fall mainly in the realm of engine, hydraulic, transmission and axle. They include, among others, alternators, starters, fuel injector pumps, water pumps, diesel fuel pumps, turbo chargers, air coolers, EGR equipment, filters and catalysts, Dolce says. For instance alternators come in different amps—80, 100, 125—as well as in different sizes. Some alternators, used on trains and buses, are as high as 350 to 400 amps.

“The alternator supports the load that the vehicle needs,” Dolce says, “so, if the vehicle runs at night and needs 100 amps to light its lights, then you want about a 125-, 140- or 150-amp alternator to provide the necessary amperage.” Wear and tear reduces available amperage, Dolce says, and would reduce amperage to 90 percent, or 90 amps, which is less than the 100 amps needed. That, in turn, puts a strain on the battery, and the alternator core, because it has to work harder, will heat up.

“Before you know it, the alternator will drop to 85 amps, to 60 amps, to 50 amps and when it gets that low it’s not going to work anymore,” Dolce says. “The life cycle of that core, in a situation like that, has deteriorated so you can’t get it back.”

Most fleet professionals recognize the importance of scheduled preventive maintenance (PM). Condition monitoring of components could well be considered a more sophisticated attack on wear and tear. The spear point backing up the line of defense is a combination of technology and analytical data.

“We call it condition-based maintenance, which lets you know how a machine feels,” says Diego Navarro, aftermarket sales manager for the Americas, John Deere Construction and Forestry.  “PM is scheduled maintenance based on hours of operation. By comparison, condition-based maintenance reacts to readings that are transmitted from the machine. Those readings can come from oil analysis, from wireless communication with a machine that is sending high-temperature data, warnings that the clutch is slipping, or alerts of water in a fuel filter and other potentially damaging conditions. All this is part of condition-based maintenance,” he says.

In addition to communications from the machine and analytical data from laboratories, condition monitoring of components also uses the human touch: thorough inspection conducted by adequately trained technicians who know what to look for. For instance, tiny leaks can be easily overlooked. Hoses rubbing against metal or other surfaces can go undetected, and differences in oil levels that can indicate potential problems can be overlooked. An over-filled engine is a sign of an “abnormal condition,” says Navarro.

“Any leak in a cylinder or a hose guarantees that you have dirt in the system,” he says. “That is 100 percent true. Many times people think there is no way dirt can get in if a leak is small. They are wrong. If you have a leak of any size, you will have dirt, and the longer you take to fix it, the more dirt the system will take in.”

Dirt, Navarro says, is “the most dangerous contaminant you can find. Silicon and aluminum and tin contained in dirt are the hardest contaminants in nature, and if you have dirt in your engine or your hydraulic system it will slowly wear out the components.”

Yet many of the hardest, most damaging particles are not easy to see, he says. For that reason, oil analysis is vital.

“If you don’t do oil analysis, you’ll never see these particles,” he says. “As a result, when an engine or hydraulic pump doesn’t reach its expected life cycle, you’ll never know why it failed.”

Technicians should also look at the condition of the oil, Navarro says. The color of the oil is important as is any sign of foam. Of all the feedback triggered by oil analysis, fleet managers should be most concerned with signs of contamination, Navarro says.

“That is a big warning,” he says. “In an engine, the worst thing you can have is coolant or fuel or dirt in your sump. Engines are prone to contamination because they are almost self-destructive devices. They suck air all day, are injected sometimes with bad fuel, sometimes technicians put bad coolant in them, and we run them all day. Since they are consumers of air, oil, fuel and coolant, something wrong can happen. Oil analysis shows the symptoms of what’s going wrong.”

Oil analysis isn’t the only tool that fleet managers can use. A $2,500 tool is available, for instance, that can do a battery capacity test for voltage and, most importantly, measure cold cranking amperage in the battery, says Dolce. “The only way to test that is to put a load on the battery,” he says. “This machine will do all the diagnostics—battery capacity, voltage drop for resistance in the circuit, and alternator charging—in five minutes or less.”

What that boils down to, Dolce says, is that a fleet manager can look at a 125-amp alternator, for instance, and see that it is putting out only 105 amps. That’s pretty close to the maximum, if you need 100 amps to operate.

Condition monitoring of components, when implemented properly, can provide major benefits for a fleet, Dolce says.

“To put it simply, condition monitoring of components will lower the overall costs of operating the fleet while increasing the overall reliability of the fleet.” Theoretically, Dolce says, you can maintain a piece of equipment and “it will last forever. You will never have to replace it. If you monitor it before it crashes and burns, you can make a conscious decision to replace the component, rebuild it, or replace the piece of equipment. The practical part is you can make sure the machine is configured to do the job. If you have a 3-yard bucket on it and you’re moving 300 cubic yards of material a day, then that’s fine. But when you go to 600 cubic yards of material, you have to put a bigger bucket on it. You can’t fabricate or modify the bucket or you could have a liability issue.”

Navarro says fleet size has a direct bearing on benefits and improvements fleet managers will see from condition monitoring of components.

“If you have a large fleet, you won’t be able to do it with paper,” he says. “You have to use a website that allows you to do tracking and gives you graphics so you can pinpoint where your alarms are. By doing that, you can assign priorities to your worst cases.

 “Many, many contractors don’t even have time to do scheduled maintenance services. Imagine if you start having numerous alarms on paper. If that happens, you won’t be able to control it. You have to do it electronically and by using electronic tools.”

Taking advantage of the benefits from conditioning monitoring of components can be realized by first looking at the maintenance cycles recommended by the OEM. Then the fleet manager should look at his particular operating environment, calculate the overall costs to maintain the equipment and how the average age figures into the productivity cycle. “Armed with this kind of information, the fleet manager can go to the owner and say this piece of equipment is X years old and costs X per hour to own and operate in our environment. A new one will cost X.”

Dolce has a personal theory based on experience that says it’s time to replace a piece of equipment when you spend more than 30 percent of its residual value to maintain it. A piece of equipment loses 30 percent of its value during the first year, Dolce says, so a $100,000 machine is worth only $70,000 before you even use it. “Each year thereafter,” he says, “it loses 20 percent of its residual value. The $70,000 machine becomes $56,400 at the beginning of its second year. You look at the history of spending and if the residual value drops so that you reach a point where you have to spend $12,000 or $14,000 to maintain a machine that now has a residual value of only $8,000, the machine will be down most of the time to do the repairs.”

At that point, Dolce says, management has three choices. One, buy a new piece of equipment with all the latest technology and reliability that can be configured to do a better job; two, rebuild the equipment; or, three, continue to repair the unit.

“The equipment manager has to forecast for the owner what it is going to cost tomorrow,” Dolce says. “For any unit that costs more than 30 percent of its residual value to repair, you know you have at least a year before it crashes and burns.”

Dolce cautions fleet managers, however, to provide company executives with management information, not accounting information. “All work orders have parts and supplies on them. That’s easy. But the labor, for instance, is not the $25 an hour you pay your technician. You have to figure out the fully burdened labor rate. A technician may work 40 hours a week, 52 weeks a year, which is 2,000 hours. That amount of hours is what you pay him for, but after you deduct sick leave, jury duty, vacation time, you are actually getting about 1,200 hours of productivity during which he turns a wrench. That’s your true cost.

 “Bean counters are zero-hour based people. Management people, however, must figure out the real cost to bill the customer, so he can make a little bit of profit. The fleet or equipment manager has to talk to top management in management-information terms and tell him what the real costs are.”

Navarro says the most important thing an asset manager can do in making condition monitoring of components work for him is oil analysis. But it has to be done on a regular basis, he says.

“You can make machines live longer if you know how the machine is wearing because you can change those conditions by repairing what is causing the wear,” he says.

Navarro says what is most important for the fleet manager is scheduled maintenance service (PM) and condition-based maintenance. “You still have to do PM,” he says, “but you have to read what the machine is telling you. Otherwise, it’s like a friend writing and asking you for help, but you throw the letter away before you read it.”

For fleet operators who want to get into condition-based maintenance, Navarro says, the first thing to do is make a commitment to do it, to understand what it is, have the tools to do it, and inspectors who are adequately trained.

There is also another requirement, he says: the ability to

listen to and study the engine, and to be able to look at its functions to see if things are working properly.

Condition monitoring isn’t anything new in the market, says Roberto Bogdanoff, field technical support and training manager with Volvo Construction Equipment. However with today’s electronics, it is easier to implement.

“Condition monitoring is basically keeping an eye on components based on machine utilization, application and the environment the machine operates in,” he says.

Every manufacturer will give you some type of life expectancy on a component, but that number is based on engineering estimates. They will always give you the best case scenario, he says.

“Take a transmission, for instance,” he says. “The manufacturer may tell you that component has a life expectancy of 1,000 hours. If you put that transmission into a machine that is hauling all day, say mulch, it may last 20,000 hours. But if you put that same transmission into a machine that is loading rocks, or any other heavy application, the life cycle of that transmission can be shorter. Life expectancy can go up or down depending on a number of factors—wear and tear, vibration, temperature, oil samplings—all these things are part of condition monitoring. The term can be summarized as systematic inspections of the machine while it is maintained. You keep track of what’s going on with that particular unit.”

Bogdanoff says anything related to the drive train and anything that can be inspected visually or by instrument should be watched closely.

 Oil sampling is critical because it monitors wear and tear. Each OEM has some type of values as to how much brass, copper or other contaminants that oil should contain to make sure the machine is “working healthy,” says Bogdanoff. Record keeping of that data is necessary to let fleet managers spot any trend.

“Our recommendation is that the oil be changed, then wait for another X amount of hours and take another oil sample,” he says. “If the condition persists two or three times, then you have a problem. If you find dirt or silicon only one time, it might be just a seal that is leaking. Condition monitoring allows you to catch those failures before they become catastrophic.”

With systematic inspections, fleet managers must have trained personnel.

“Technology today is similar from machine to machine,” Bogdanoff says. “Everybody [is trying] to make it a little bit better. But you need to know the specifics of each machine. Sometimes you find, for instance, that a pin is worn. All you have to do is change it, which takes two or three repair hours, and you’re good to go. However, if you don’t do anything and wait until the thing falls apart, now you’re talking about three days of repair that costs $10,000.”

Trained personnel can spot something like a worn pin, but untrained technicians may not even look. That’s why Bogdanoff says that any company should have a training management program.

“Unfortunately, very few do,” he says. “Not having a training plan causes a lot of issues. If you get a machine in the yard and realize you have no idea how to make the repairs, that’s a reactive plan.”

A situation like that can be avoided by condition monitoring. “That’s when it really becomes important,” says Bogdanoff. “When you have a $30,000 or $40,000 engine in a machine, you have to take care of it correctly. To do that you have to know what the heck you’re doing. Otherwise you can make a bad situation worse.”

Fleet managers/owners must also invest in technology—computers and software programs—that enables them to implement component monitoring.

“You have to spend the money,” Bogdanoff says. “Technology takes money. Training many times is viewed as an added expense. There’s no way around it, and if you take advantage of your full investment you will see that the benefits of condition monitoring convert into dollar signs.”

A contractor who spoke recently at an AEMP meeting says his company didn’t know how to do condition-based maintenance until it decided to try, Navarro says. When Navarro went to one of the jobsites and spoke with a machine operator, the operator told him he had been complaining for two years that the grease zerks did not take grease, that bolts were missing, and there was a leak in the valves, but no one had fixed the problems.

Navarro says condition-based maintenance affects fleet operations “big time.”

“If you do condition-based maintenance, your equipment costs per year will be half of that of reactive maintenance,” he says. “The cost of doing condition-based maintenance is one-third cheaper than those who do preventive maintenance only. The big impact is machine availability. Uptime is going to be improved because you will be preventing failures by replacing components before they fail.”

As the contractor told Navarro, he hired the right person, purchased the software that was needed, began using oil analysis on a regular basis, and now he has implemented true condition-based maintenance. “Before,” Navarro quoted the contractor as saying, “we just extinguished fires. Now we don’t even let the fires start.” EM

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