November 1, 2012
Keep your Interim Tier 4 diesel engines running strong with a comprehensive preventive maintenance program.
By Tim Hilvers
As the power source for an array of heavy-duty equipment, diesel engines are vital to profitable production in the aggregate industry. Producers rely heavily on these engines to perform day after day in rugged, often extreme, environments.
By implementing a comprehensive engine preventive maintenance program, equipment managers can help maximize the reliability of the engines that are so critical to their operations. Any complete program includes maintenance considerations associated with engine technologies used to meet new Interim Tier 4 emissions regulations.
Your engine is a fully integrated system of components that work together to deliver optimized performance, so maintaining your engine’s fuel, lubrication, air intake, cooling, electrical, and after-treatment systems properly will promote a long, productive service life.
The operator’s manual provides a detailed description of recommended engine service requirements at various intervals. Following these service requirements will help ensure that your engine delivers years of dependable service.
The integration of exhaust filters into Interim Tier 4 engines for particulate matter reduction necessitates the use of ultra-low sulfur diesel (ULSD) — diesel fuel with a sulfur content of less than 15 ppm. Using diesel fuels with sulfur content greater than 15 ppm can damage the exhaust filter, leading to early replacement.
Some Interim Tier 4 engines also operate efficiently with biodiesel blends, providing fuel-choice flexibility. If you opt to run biodiesel, a 5-percent blend (B5) is preferred, but a biodiesel concentration of up to 20 percent (B20) may be used. Regardless of biodiesel blend level, verify with your fuel provider that the biodiesel blend meets ASTM D6751 (U.S.) standards.
Use only fuel additives that are approved by the engine manufacturer. Regardless of what fuel or additive you use, frequent fuel sampling and analysis is a good fleet management practice.
Fuel quality is essential to Interim Tier 4 engine performance and reliability. In addition, an unrestricted and uncontaminated fuel flow is, obviously, very important in ensuring the proper operation and long life of your diesel engine.
Therefore, when performing fuel system maintenance, remember the following best practices.
• Check for leaks.
• Check for bent, kinked, or dented supply or return.
• Inspect fuel filters for dirt, water, or other foreign matter.
• Use quality fuel that is not contaminated with water. Water in the fuel system is the greatest cause of fuel injection system failure.
• Check for water in the fuel filter. Daily inspection of the fuel filter and draining the water from the fuel filter water separator and fuel tank as required will ensure that the fuel system is protected.
• Install a fuel storage tank water-separating filter to further protect engines by filtering out dirt, rust, and scale. To service the tank filter, install a shutoff valve between the tank and filter. The filter element should be changed annually or more often if fuel flow becomes restricted.
Well-designed machinery lasts a long time if cared for properly. This care is especially crucial where lubricants protect critical components. Following engine manufacturer recommendations for high-quality lubricants and periodic maintenance can prevent machinery from wearing out prematurely.
With the introduction of exhaust filters in many Interim Tier 4 engines, the type of engine oil used can have a significant impact on the proper functioning and ash service life of these devices. Use only engine oils that meet API CJ-4 and ACEA E9 standards. These oils are refined with a lower trace metal content, which reduces ash accumulation and increases exhaust filter service life.
Lab and field tests reveal that the superior anti-wear additives in quality engine oils can significantly reduce engine wear, increasing the productive life of the engine. They also extend drain intervals and reduce piston deposits, which lead to a cleaner engine that will last longer and provide consistent power.
Unfortunately, all lubricants gradually lose effectiveness during operation due to chemical and physical changes in the lubricant. The deterioration process is accelerated by contaminants from external and internal sources. That’s why following manufacturer-recommended lubricant change intervals for normal operating conditions is so important. More frequent changes are recommended when operating in extreme environments, such as in very hot or dusty conditions, or at high altitudes. Oil analysis can be performed to ensure that the recommended service interval is adequate for your application.
Keep lubricants clean. Even the best lubricants cannot function properly if they are dirty. Be sure to do the following:
• Change oil when recommended;
• Keep all lubricant containers covered in an area protected from dirt and moisture; and
• Remove all dust and grime from both the container and service points before performing lubrication service.
Regularly scheduled oil sampling and analysis can pay for itself by detecting potential problem-causing conditions before they turn into costly downtime.
Making sure your engine receives an unrestricted flow of clean air is imperative for proper operation. For example, dust reaching your engine through a leaking connector in the air-intake system — called “dusting the engine” — can completely destroy an engine. Therefore, it is important to take the following steps.
• Inspect the entire air-intake system for openings that could draw in unfiltered air (loose clamps, cracked hoses, etc.).
• Inspect dry-element type filters and replace if clogged with dust or dirt. Inspect for damaged seams and pleats. Replace if damaged. Cleaning the elements with compressed air or by pounding them on a hard surface is not recommended.
• Replace highly efficient PowerCore-type filters when they become restricted; they cannot be cleaned.
When performing maintenance on your engine’s cooling system, always use the recommended class of coolant. It is important to be selective with antifreeze/coolants because not all of them provide the protection needed to operate efficiently under extreme pressures and temperatures.
Use a fully formulated antifreeze/summer coolant designed and extensively tested to protect wet-sleeve-liner diesel engines from cylinder-liner cavitation erosion. This is especially critical for heavy-duty, off-highway equipment in the aggregates industry that often endures punishing conditions and temperature extremes.
Engine cooling systems should be thoroughly flushed and cleaned with a heavy-duty cleaner and refilled with clean coolant and inhibitors per the operator manual’s recommended interval. In addition, it is important to visually inspect the radiator and thermostats for any signs of corrosion, debris, or physical damage.
Coolant solution analysis is highly recommended. It will verify the chemical composition of your coolant and include a written report with maintenance recommendations for the coolant and cooling system.
Also, make sure to do the following:
• Replace radiator hoses that are cracked, soft, or swollen;
• Clean all dirt and trash from between radiator fins and around the radiator itself;
• Check for bent radiator fins and straighten as needed;
• Ensure baffles and fan shrouds are in place and functional; and
• Inspect the fan blades for damage, the fan belts for excessive wear, and replace as needed.
Maintaining the electrical system is often more complicated than maintaining some of the engine’s other systems, so most maintenance tasks should be left to a certified mechanic. However, an engine’s electrical system is centered on its battery, and it is always important to check the condition of your battery.
• Verify batteries are fully charged and the electrolyte is at its proper level.
• Remove battery cables and clean cable ends and posts.
• Repair or replace the alternator if it isn’t keeping the battery fully charged.
• Check all alternator wiring connections for tightness and corrosion. Correct as needed.
• Check all chassis grounding and bonding wires for corrosion and integrity.
• Check condition and tension of alternator belt, and adjust or replace as needed.
• Check all starting motor connections for tightness and corrosion. Correct as needed.
Maintenance to remove accumulated ash is a key system health component of your Interim Tier 4 engine’s exhaust filter. The exhaust filter must either be replaced with a remanufactured component or cleaned by a certified exhaust-filter cleaning facility at the appropriate interval.
Contrary to what some end users think, Interim Tier 4 engines do not necessarily require more maintenance than their predecessors. In fact, some manufacturers have been able to maintain or improve on Tier 3 maintenance intervals depending on the application and machine type.
By establishing and diligently following a preventive maintenance program, equipment managers can help ensure the optimal performance, reliability, and longevity of their engines.