Getting Ready for the Dog Days
Engine and equipment maintenance should be year-round if an operator is concerned with the bottom line. Summer brings greater workloads but little incentive, perhaps, when it comes to sustaining the most expensive parts of our operations: machinery and engines.
Engines are expected to last a long time and perform well despite the brutal circumstances under which they must operate. Maintenance does influence engine life and reliability ultimately.
“For contractors, uptime is the most important aspect of a piece of equipment in their inventory. It’s difficult to bear costs when machines are idle,” says Bruce C. Farrar, manager of off-highway communications with Cummins Inc. “Engine preservation comes down to reactive maintenance, preventative maintenance, or predictive maintenance. ‘If it ain’t broke, don’t fix it’ doesn’t mean don’t maintain it either. We don’t plan for breakdowns, but they often occur at the worst possible times.”
Minding the Lubrication
“The lubrication system should be looked at daily as should air-intake and cooling systems,” says Farrar. “You should also be paying attention to your fuel and electrical systems.”
In addition to checking oil levels, brands with known quality backgrounds should be used. Never mix brands or viscosities of oils, according to Farrar. The formulations can be different and have a negative overall impact on oil’s ability to protect the engine.
“Oil breaks down over time, gets soot in it, and acid is generated by the running of the engine as well,” says Farrar. “All of these things are what break down the lubricating principles of the oil. Keeping an engine filled with good oil that meets the oil and hour spec indicated within your O&M [operations and maintenance] manual will increase the overall engine life potential.
“An oil filter really should be filled with oil prior to spinning it back on the system. The oil should also be poured into the side with the small holes or the ‘dirty’ side of the filter; if you pour it into the center you’re pouring it into the clean side, and this means you can be introducing dirt into the system. By pouring into the side, any dirt unintentionally introduced into the engine will be filtered by being caught by the filter media. Also, side-pouring ensures lubrication reaches the system more rapidly.”
Any and all openings around a lubrication system, such as the filler cap, dipstick, oil-line connections, or oil tank, must be kept as clean as possible. Even something as simple as checking oil with a dipstick may introduce dirt into the system if the area surrounding it is grimy or caked with muck. Most ring and bearing failures are caused by dirt introduced to the engine.
|Performing daily preventive maintenance helps contractors avoid unexpected breakdowns.
Pete Pawluk, service manager of Stafford’s office in Ashland, VA, suggests it helps to keep engine drive belts in good condition and adjusted properly. It’s also a good idea to keep clean coolant in the system. Air filters should be checked daily, he says, and the machine should be operated at the appropriate level for completing a particular job.
“For example, you don’t need to run an excavator at its highest mode if you’re doing finishing work. Operators shouldn’t idle engines all the time either,” says Pawluk.
Pawluk recommends checking pressure on the cooling system during the slow times before summer, replacing questionable hoses and engine accessory belts, and back-flushing the cooling system (especially the radiator), as well as a complete service on all major components: engine, transmission, and hydraulics. “If those systems are operating improperly, these items can create more demand on the engine and make it work harder, thus creating heat in hot months.
“Another possibility for the slow times is to use this period for formal training, in-house or out, at service schools. Now is the time for operators’ schools and gaining any applicable certifications.
“Training is the key. I hate to say it, but I see quite a few people working at a job site, and they don’t understand the equipment they have to work with and its capabilities. A lot of them will not read the operator’s manual in that equipment. I get a lot of phone calls on items that could have been answered by a manual before calling. Many equipment dealers will conduct training sessions on their customer’s equipment, but the customer must take the initiative to ask their dealer for this in the first place.”
When it comes to the new Tier III engines, manufacturer engineers researched and designed them the way they are for a reason, according to Pawluk. “If there is a problem with a component or system, fix it by the manufacturer’s guidelines and procedures; shade-tree mechanics or bubble-gum patches must remain a thing of the past.”
He also recommends keeping the equipment clean. Pressure washing is great, but keep it easy on electronic components like electronic control modules and controllers. Cleanliness is the best tool owners have to prolong the productivity of their equipment. “Good housekeeping is also important inside cabs; it is hard to cool a cab with clothes, rags, magazines, empty soda bottles, and trash thrown behind the seat,” says Pawluk.
Air Filtering Systems
The dusty, grimy, dirty air is all some engines have to breathe where heavy construction’s occurring. Hole-ridden air filters gulp in dust, leading to dust-out engine conditions and failures associated with the accelerated wear of rings, bearings, and related components.
When changing a filter, never simply remove it: Clean it and place it back on the machinery. Likewise, blowing compressed air on a filter, a common practice, is in actuality tearing the filter media and subsequently introducing larger holes into the air filter—and more contaminants into the engine.
Blowing an air filter clean or banging it on the side of an engine to clean it, though it may have worked in the old days, is definitely not a good idea nowadays. “We always suggest operators inspect their engines before running them,” says Farrar.
|Inspecting and keeping machinery clean ensures maximum efficiency.
This means inspecting, especially, the clamping and plumbing of the air-intake system, too. Loose clamps may allow unfiltered air to enter the engine and rub holes in the intake. Dirt and dust enter the power cylinder, and the ring surfaces will wear beyond the control of oil. A simple visual inspection often determines if there are any loose air intakes. Rusting brackets and cables may indicate that air is entering the system or there is a break.
An air-restriction monitor can be installed, if needed, to aid in determining when the filters ought to be replaced. This measures when things are getting too dirty for air to flow effectively. Though, in general, the manufacturer’s suggested schedule for changing should be followed, an air-restriction monitor may indicate if it needs to be changed earlier.
Cooling and Fuel Line System Upkeep Critical
Radiators should be inspected daily. Debris reduces the amount of airflow through the radiator, causing the radiator to get hotter and hotter. Many Tier III engines now have incorporated the high-pressure, common-rail fuel system. This is a fuel system with a common rail or fuel reservoir that fills up and is under pressure. The ejectors are electronically controlled, so there is the capability in a tightly controlled way to inject the fuel at high pressure into the power cylinder.
Things such as optimizing the combustion create an environment where the power is peak, emissions are correct, a smoothing-out of the diesel detonation occurs, and noise reduction can be managed. But with that also comes higher tolerances for the fuel system. Filtration therefore needs to be where it should be so that any water debris or contamination doesn’t occur.
“This leads to many, many problems with high-pressure fuel systems,” says Farrar. “Tolerances are so much tighter that we’re filtering down to the 3- and 5-micron level for the fuel system. It requires for the injectors a very clean fuel going through it. High-pressure debris sent through it ultimately destroys the injector, and you’ll have over-fueling problems beyond meeting the emissions standards. Over-fueling can at last destroy an engine.”
Engines should be checked for moisture each morning, and any water should be drained off each morning before machinery is started. Fuel filters, too, can be frequently checked for water and drained as necessary.
Predictive Maintenance to Avoid Future Headaches
Predictive maintenance can be critical for equipment such as mining excavators, which run around the clock to haul materials. These machines must have 98% availability or more, 24 hours per day, seven days per week, and 365 days per year. There’s a vested interest in staying up for mining millions of dollars’ worth of product over time.
For such work, regular oil analysis may be critical. Engine oil is analyzed to see where the thresholds for such contaminants as soot, acidity, or even metal wearings are starting to appear in the oil, not only to help operators understand what’s the correct change interval, but also to see when components begin to wear or whether they are showing wear earlier on.
In that case there may need to be an understanding that a failure is on the horizon. Work can then be scheduled ahead of time for the particular piece of equipment. This type of maintenance may involve more cost up-front.
Improper or corroded electrical connections are often overlooked but may cause poor grounding, which reduces electrical efficiency, and may cause bearing damage in the engine as the electricity seeks to ground through the starter. Proper grounding in engines extends their lives. A small grounding problem can easily be diagnosed as a sensing problem, with fault codes showing up all over. But in reality it’s a problem with voltage variations that result from a bad grounding.
John Golka, product support manager with Sakai America Inc., agrees with others who suggest that the best thing an operator can do to prepare the machine is to follow the operator’s manual and do the daily checks. “Most of the bigger contractors use a checklist, which hopefully is based on the manufacturer’s recommendations. The list should include [checks for] proper oil levels, radiator levels, radiator cleanliness, inspecting for leaks, inspecting the fuel separator, fan belts, and, of course, any safety features.
“Again, follow the manual and change the fluids when recommended with the proper viscosity for the climate. Check the radiator on both sides. Operators and technicians should also pay attention to which way the fan blows through the radiator. If it blows through the inside, it will tend to collect more debris than if it pulls from the outside.”
Golka suggests colder months and slower operations should mean operators and maintenance people have more time. They should be enabled to do a more thorough job of servicing.
“Whether a Tier III engine is used or not should not change the fact that we still must keep the proper fluids in it and change those when recommended,” says Golka. “My thumbnail advice in nearly all situations: Always read the operator’s manual for your equipment; there’s always lots of good, useful information in there.”
John Deere’s COOLSCAN service will analyze a sample of engine coolant to determine if its condition requires an additive package or a total replacement to ensure the lifespan of the equipment, according to Grant Suhre, John Deere field service manager. Coolants that are specifically formulated for heavy-duty diesel engines are available; automotive coolants are not sufficient.
“In the off season, along with the coolant testing you can do cooling system maintenance,” says Suhre. “If you need new radiator hoses those can be inspected and replaced at any sign of damage or breakdown. Check the thermostats—testing them to be sure they’re operating correctly first—and the radiator itself should be cleaned and inspected for damage, corrosion, and bent fins. All those problems can be addressed now, as well as an inspection of the fuel, hydraulic oil, Intercooler, and air-conditioning heat exchangers throughout the machine.”
Suhre points out that oil analysis can be done to ensure oil remains in good condition. A preseason oil change is a good idea, too, as it saves time in doing this before the busy season. High-viscosity diesel engine oil is advised for summertime use. As a good maintenance practice it makes sense to align the fuel system filtration servicing with that of oil changes.
John Deere systems may be unstacked with hinging, clips, or retainers for easy removal of debris between them and for cleaning both sides of all heat exchangers. The company’s new Tier III engines contain coolant over-temp alarms and air-filter restriction monitoring systems that may be enabled depending on the machine application. Onboard diagnostics warn of many different variables through the fault-code system. Automatic power reductions or shutdowns occur if certain operating temperatures exceed maximum limits for a certain length of time. This allows the engine to protect itself from permanent damage if heat exchangers become blocked or get damaged.
“We find perhaps the number-one preventable early failure mode of off-road diesel engines comes from dusting due to improper air-filter maintenance,” says Suhre. “That can include a physical breach in the air-filter system which may have been overlooked during inspections.”
|For long equipment life, follow the manufacturer's guidelines.
Southern Georgia tends to get a little bit warmer a little bit sooner, according to Gene Medeiros, product support manager with Stafford in Tifton, GA. “We recommend our customers bring their equipment into the shop before the extremely hot weather hits.
“We’ll change all fluids and filters, of course, inspect the A/C system, perform a safety inspection, and recommend any fixes needed. Then we’ll also do required repairs. February or March is the time to do this. In our area the equipment is already on the way out to the fields by the latter part of February.
“We don’t recommend the use of an independent mechanic. Such individuals simply do not have the training our people have. The equipment today has become very complex. The manufacturer’s warranty will also be voided in such cases, and you’ll usually end up with a large repair bill as well. Something else I strongly advise against is using machinery to lift more than its recommended capacity.”
Glow plugs are included in engines today as a starting aid for quick starts year-round. Medeiros also advises against the use of ether as a starting aid if an engine contains glow plugs. “When ether explodes in the cylinder, force is created and this can fracture a piston ring or stretch the rocker-arm bolts.
“Overall, my advice is to be sure to follow the manufacturer’s guide for servicing the equipment, buy original equipment filters, use the manufacturer’s recommended fluids in engines, transmissions, and hydraulic systems, and you’ll get the peace of mind on how long your equipment will last. You can use the inferior oils and fluids and your equipment will run, but as the years go by, equipment just won’t last as long as it would if you used what manufacturers specify.”
He suggests inspecting air filters after every 100 hours of use. “It’s OK if it’s a little bit dirty. When dirt gets into the filter, into the pores and holes in the media, it actually plugs them up somewhat and you get better filtration than when the filter is brand new. Much depends on application. In high dust and high dirt, keep those filters changed. Same goes for your A/C, radiator and A/C compressor or condenser: Be sure to routinely keep those blown out with air.”
In southern Georgia fire ants are a real problem—and a growing problem around the United States. They can attack distributors and evaporator-dryers of the A/C units easily. Especially if equipment sits for a week or so, there is danger from infestation. Sandy environments can also affect an engine and must be guarded against. Piney chip-yard applications demand constant maintenance and changing of filters thanks to the presence of highly flaky bark. The dust is sticky and sappy and can quickly gunk up equipment.
Fans Help With Cooling
The Huber Reversible Fan requires little maintenance other than routine lubrication, according to Mark Ditrich, manager with Huber Reversible Fan Inc. of Erie, PA. Huber manufactures fans from 16 inches to 60 inches in size. Actuating the fan—or reversing it once a week or whenever the machine is serviced—helps prolong life. The Huber fans are all manually reversed; there is no electrical switch, hydraulic system, or air system to power a reversal. Each individual blade can be pushed in by hand and simply rotated to the opposite position, where it will snap into place, thus changing the airflow from blower to suction.
“Usually what happens to a reversible fan is it gets left in one position for a period of months or even years without reversing it or lubricating it, and shafts may seize, making it difficult to switch from blower to suction or vice versa,” says Ditrich.
“In dusty environments the fan will reverse to clean out the radiator. But usually, since there’s not maintenance required, they don’t get reversed. This is what causes them to lock up. In the summer it’s best to have the fan in the blower position for cooling, while at other times of year the sucking position works better for drawing dirt and dust away from the engine.”
In a nutshell, in the summer it’s best to have the fan in the blower position for cooling by taking the heat of the engine away from the operator. Also, in the blower position the fan will blast dust and dirt out of the radiator.
Keeping the engine free of debris helps it run more efficiently. In colder times of the year or cooler times of the day, from morning to afternoon, it’s best to have the fan in suction mode as that position draws the heat of the engine toward the operator, offering comfort as well as keeping equipment from freezing up in severe winter weather and saving on downtime.
Advice From a Dozer Specialist
Chuck Murawski, Komatsu senior product manager for dozers, firmly believes crawler-dozer operators should perform all work according to maintenance sections in the O&M manual. On the Komatsu D65PX-15, for example, clean the cooling system thoroughly (radiator, oil coolers, air-to-air charge air cooler, and air-conditioning condenser). Also, be careful to avoid bending the fins since this will restrict airflow. Clean all perforations in doors and covers around the machine so air flows through freely.
Lower and clean the underguards (belly pans), because built-up dirt and debris can act like an insulator, thereby preventing power-train heat from dissipating. Be certain that engine coolant is at proper level and concentration. “Normally, 50% concentration is adequate, but consider 30% for ambient temperatures that consistently exceed 100 degrees Fahrenheit, because heat transfer will be improved,” says Murawski. “Be sure to have engine oil and other fluids comply with the ambient temperature chart in the O&M manual. The Komatsu engine air-filter housing has an air-restriction indicator that operators should read to determine when to clean or replace.
“It doesn’t hurt to replace critical parts—coolant hoses, fuel hoses, high-pressure hoses, engine belts—according to intervals mentioned in the manual, as well as installing clean cab filters and checking A/C charge pressure. Be sure to grease all joints and adjust the undercarriage to the specs in your maintenance guide.”
All Tier III engines have air-to-air charge air coolers, according to Murawski, so the cooling fan now has an additional component to pull air through. Komatsu has added access holes on each side of the cooling system, so operators can insert an air or water hose and blow debris outward from the middle. All Tier III engines also have hydraulically driven reversible cooling fans, so Komatsu recommends reversing the fan on a regular basis to purge debris. Also, the radiator and oil coolers are now made of aluminum for better heat transfer.
“Be careful when washing the machine that you don’t spray high-pressure-jet water directly onto main electrical components,” adds Murawski. “Komatsu seals all electrical components and uses DT-type waterproof connectors on all wiring harnesses for improved reliability, but it is prudent to avoid high-pressure washing.
“It doesn’t hurt to check the batteries for proper fluid level and the alternator belt for proper tension to ensure the electrical system charges properly. It seems like a lot to remember, but if you take time to perform these preventive maintenance steps, your Komatsu machine should be all set for whatever summer has in store.”
Gary Jenkins, Stafford service manager in Charlotte, NC, advises operators not to wait until the beginning of the hot weather to check out air-conditioning systems. “Turn it on before the weather is unbearable. A trial run helps determine if it’s performing as it should be. Now is the time to do this.”
Jenkins feels too that filters for A/C units—especially those located in the back of cabs—are often overlooked. “We’ve often received calls reporting a loss of cooling only to discover an A/C filter they didn’t know about was stopped up. Despite needed required maintenance service, many people don’t worry about this until the A/C system stops working.”
When it comes to the Tier III engines, a mechanic must be savvy with diagnostics around the new high-pressure fuel systems. “The old days of crack-a-fuel-line-to-fix-a-problem are over,” says Jenkins. “I’ve heard people say that if you crack a Tier III fuel line now you’re going to have to replace it. In a recent discussion with the manufacturer, they stated that a break in the line or loosening of the line would be very dangerous, possibly causing serious bodily harm.
“Today’s mechanic must be smarter and better trained on the proper maintenance and test procedures on these engines. The best operator may not always be the best reader of an equipment manual; but that’s also a very important step no matter how well that operator can move the levers and handle the equipment. Don’t forget about what is known as the in-line fuel or ‘rock-stopper’ filter. That can cause a lot of people to think their engine has major problems with power loss.”
As machines grow “smarter,” service technicians often can troubleshoot right over the phone. “This is an asset to a construction operation, as there are people on the job,” says Jenkins. “Time and money can easily be lost when people are waiting for a callback.”
Don’t Forget the Loose Ends
Chad Ellis, training manager for Doosan Infracore America, echoes what others have mentioned. He suggests keeping clean cabs on machinery and regular cleaning or replacement of cab ventilation filters. This is also a good time to check the air-conditioning charge and to inspect the condition of the condenser and cooling system hoses.
Also it’s important to pressure-test the radiator, flush the radiator, and replace the coolant. “While ensuring that fluid levels are to specifications, it wouldn’t be a bad idea to inspect and service drive belts and pulleys and clean and service radiator and oil-cooler veins to ensure optimal air flow,” says Ellis. “Don’t forget to inspect and/or replace radiator fans, radiator and engine compartment insulation foam or rubber seals to ensure proper air flow through the cooler group. Also, during slow times, it is not a bad idea to inspect batteries, battery cables, terminals, and ground connections.”
Ellis suggests removing all debris accumulation from all heat-generating components, including engine compartment, hydraulic pump compartment, battery compartment, and swing motor and control valve areas. Replacement and repair of all faulty hydraulic lines, fittings, and clamps are critical as well.
“Pressure-washing of the engine and cleanup of hydraulic pumps is always a good idea,” says Ellis. “Inspect and service the swing bearing cavity—i.e., draining of water or oil from cavities—and lubrication to specifications helps, too.
“We always inspect and service undercarriage group, drivetrain. This may not be mentioned as much, but it helps to inspect and protect all main electrical harness connections with dialectic lubricant, secure all loose or dangling harness wires to prevent damages, and inspect and service pump-drive couplers.
“Frequent air-filter inspection and cleaning are just as important, if even more so, for the Tier III engines. I would add that strict compliance with fuel-filter change intervals be followed as well. It’s also important to implement clean fuel quality control measures: i.e., bulk storage fuel, fuel trucks, and refueling points and containers for engines in general and especially these new engines.”
“These may seem like picky things to remember,” says John Deere’s Grant Suhre. “But, on the other hand, a complete engine replacement will ruin your day. When maintenance items are ignored, the damage that is caused can be very expensive to repair and can cause extensive downtime. That’s the bottom line. Our manuals provide detailed instructions for maintenance of all these different systems. Clean air; clean, fresh oil; clean, fresh coolant; and clean, fresh fuel are the things that will keep you running well. Just keep those in mind.”
Peter Hildebrandt writes extensively on engineering and scientific subjects.