LO 6-10 Identify and describe clean care practices

1. Clean Care Service Practices

Clean Care Service Practices Diesel engines and fuel systems are highly sensitive to contaminants such as dirt and water. While engines have always been adversely affected by wear factors caused by contaminants, smaller operating clearances, higher injection system pressures, and use of electrohydraulic components (the result of advances in technology) cause even the smallest amount of contaminants to be more destructive in today’s engines Figure 41. Large heavy-equipment shops operating underground were the first to discover the benefits of what are commonly called clean care practices. This means that before servicing any engine or fuel system components, such as injectors, fuel lines, high-pressure fuel pumps, and so on, it is critical that no contaminants enter the fuel system or internal engine component Figure 42. By implementing shop practices to eliminate contamination of fluids, such as fuel and lubricating oils and internal engine components, the amount of money saved is many times more than the investment costs needed to establish clean care practices. Clean care shop practices extend the service life of replacement parts and major components and also reduce maintenance costs through longer component service life and increased equipment productivity or uptime. From a business perspective, clean care practices have the added benefit of increasing resale value and return on investment (ROI), lowering overall lifetime costs of operation, and increasing productivity; the vehicle will provide more efficient service with improved reliability Figure 43.

FIGURE 06-41: The operating clearances and pressures of fuel system parts make them more sensitive to premature wear caused by contaminants.

FIGURE 06-42: It is critical that during service, all high-pressure injection lines and fittings are capped to prevent entry of contaminants. Do not remove caps until it is necessary to reconnect fittings and lines.

FIGURE 06-43: The relationship between preventive maintenance costs and resale price.

1.1. Clean Care Service Practices

Clean care maintenance reflects the understanding that the cost of preventing an unexpected breakdown or premature failure is usually much less than responding to an unexpected failure. These two approaches to maintenance are called proactive or reactive . When proactive maintenance processes are followed, small problems are corrected before they turn into bigger, more expensive problems that cause unanticipated downtime or liability Figure 44. Reactive maintenance strategy means service is performed only after equipment has failed. This approach may keep vehicle and fleet operating costs low, but only temporarily TABLE 6-1. As time passes and distances traveled are increased, repair costs exceed the costs associated with proactive maintenance and vehicle uptime falls Figure 45. Unexpected failures, faster component wear out, consequential damage from failures, and downtime caused by unexpected repairs drive up maintenance costs for vehicles on which preventive maintenance (PM) is not performed.

FIGURE 06-44: The difference in maintenance costs before and after a failure.

FIGURE 06-45: The cost of maintaining a vehicle with and without preventive maintenance.

1.2. Clean Care Service Practices

The most important opportunity for extending component life and lowering operating costs is to effectively manage fluid cleanliness. The ISO establishes standards for minimum cleanliness of fuel at the inlet of high-pressure injection pumps. According to the standard, a 208 L (55 U.S. gallon) drum of fuel has less contamination than the weight of a regular-strength Tylenol capsule (160 mg).

Before servicing any engine or fuel system, prior to disassembly, important steps are taken to clean the area around the component, the component’s fittings, and the mounting hardware. Dirt or contaminants can be introduced into the fuel system and engine if the areas surrounding the components are not cleaned, resulting in damage to the fuel system and engine. This begins by thoroughly washing the engine area prior to service. Washing helps to keep contaminants out of the shop where they can transfer onto an open engine. Power washing the engine and engine compartment minimizes the likelihood of dirt entering an open engine.

Other practices include:

• Sealing the ends of hoses with caps or plugs immediately after disconnection and verifying that they are cleaned prior to reconnection. Good practice: using plastic or metal plugs and caps. Acceptable practice: hose ends are taped over. Neglecting the use of caps, using rags stuffed in cavities/openings, or taped-only open oil lines and ports is NOT recommended.
• Injectors are also capped and plugged until they are installed in an engine. Injectors should be handled with gloved hands to prevent the transfer of skin oils that can corrode sensitive injector parts.
• Cleaning solvents for fuel system parts must not leave residues, and electronic contact cleaner is preferred.
• Carbon and dirt in an engine is vacuumed up with a shop vacuum rather than blown away with compressed air when cleaning the inside of an engine.
• Technicians must work with nitrile or latex gloves, which can be kept cleaner than hands without gloves.
• Technicians receive specialized training in clean care policy and service practices. This includes establishing new levels of cleanliness and organization of shops to prevent contaminant transfers. Gone are the days when technicians worked in dirty coveralls in filthy shops. To clean up spills, absorbent mats (rather than granular absorbents) are used. Unlike absorbent pads, granular absorbents contain very abrasive particles. Technicians are instructed to clean funnels prior to use (to prevent fluid contamination); to practice dry installation and priming of fuel filters; and to practice proper handling, disposal, and storage of all shop fluids.
• Parts are kept in packaging prior to installation. Parts are also stored in sealed drawers, not in open bins where they can collect dust.