This is the third and final part in the series of articles providing advice for maintaining and analysing the condition of engine oils, hydraulic fluids and coolant in equipment.
In the June 1 issue of Logging-on, Case gave advice on general fleet best practices for engine oil and hydraulic fluid use. In this issue we examine DEF and modern coolants:
DEF: Many modern Tier 4 engines use Selective Catalytic Reduction (SCR) technology to meet emissions standards. This requires the use of diesel exhaust fluid (DEF). DEF is injected into the exhaust stream and converts emissions into nitrogen and water. DEF is made up of 67.5 percent de-ionized water and 32.5 percent high-grade synthetic urea, and is safe and easy to handle. However, DEF must be managed properly for peak system performance. Good management of DEF protects it from evaporation and extreme temperatures, and prevents contamination. Machines that use DEF have sensors to analyse the DEF quality. Any problems caused by evaporation or contamination will trigger a fault code. The injectors that meter DEF into the exhaust stream are precision instruments with tight tolerances similar to fuel injectors. Most SCR systems have a cartridge filter to protect the injectors. Keeping DEF free of all contaminants will help ensure maximum filter life. The filter inside the DEF pumping module should be changed at 1,200 to 1,500 hour intervals. This filter must be changed at the correct hours. The first indication of contamination is cloudiness, discoloration or the presence of particles. The correct storage of DEF is important. Some components of the fluid degrade from harsh sunlight or extreme temperatures. DEF can also be contaminated by containers and pumping systems. Dedicated containers that were manufactured specifically for DEF should be used. They should be rinsed and sealed. When stored properly, DEF can maintain its qualities for around 36 months.
OAT Coolant: Tier 4 diesel engine technologies have expanded the market for new engine coolants, which create higher combustion temperatures and cylinder pressures. Many Tier 4 Final machines use Organic Acid Technology (OAT) coolant, which is a form of extended life coolant. Its primary benefit is increased protection to the engine and better performance over its service life. Factory-filled machines will have a decal near the fill point. This will indicate the use of OAT coolant and its brand or formulation. This ensures that conventional coolants are not mixed with OAT coolants. It also tries to prevent other brands of coolants being used as they might not match the spec of the factory coolant. If the coolant type is changed, the system should be flushed three times before adding the new coolant. It’s also important to use only distilled or de-ionized water when mixing coolant from concentrate, as other waters will lower the protective capabilities. Source: http://www.casece.com/en_us/News/Pages/Fluid-Management-Best-Practices-for-Construction-Equipment.aspx