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UNDERSTANDING YOUR ENGINE’S EMISSIONS COMPONENTS
Your Cat® Tier 4 Final diesel engine reduces harmful nitrogen oxide emissions to meet government standards without compromising the efficiency and performance you expect. But when maintaining your equipment, what do you need to know about your engine’s emissions components?
Your engine’s features like precise injection timing, the Cat® NOx Reduction System and aftertreatment tech like the Clean Emissions Module increase fuel economy while shrinking environmental impact. Best of all, they're designed to be so efficient and easy to maintain that it won’t affect your daily work at all.
The basics
In the Cat® Tier 4 Final engine, some NOx emissions are oxidized by the diesel oxidation catalyst. The engine reduces the amount of particulate matter that reaches your aftertreatment system. A diesel particulate filter traps particles that enter the exhaust stream. If soot builds up, the Active Cat Regeneration System activates to remove it. This all happens automatically without interrupting your work.
Diesel exhaust fluid (DEF)
DEF is used in all 175-750 horsepower Tier 4 Final engines. This fluid is injected into the exhaust stream, mixing ammonia with NOx and converting NOx emissions to nitrogen and water vapor in the selective catalytic reduction system. This may sound complicated, but maintaining this equipment is simple. Just fill up your DEF tank every time you refuel your machine. That way, you won’t find yourself out of DEF during a busy job. Keep up with your DEF levels the same way you keep up with fuel levels: pay attention to the gauges in your cab.
Need more information on gauges and lamps? Check out this video:
DEF basics
Here are three basic tips to remember about DEF:
- It can freeze in cold temperatures. When you shut off your machine, the DEF is emptied out of the line so it won’t freeze between shifts. It will freeze in the tank, but a heater will thaw your DEF automatically at startup if necessary.
- Make sure you use the right kind of DEF. Cat equipment is designed for commercial-grade DEF that meets ISO 22241-1. This is easy to find at your fuel and oil retailer of choice.
- Contamination control is key. Keep the DEF tank filler cap and the area around it clean. Don’t fill up your DEF tank with dirty containers or funnels. And don’t overfill your DEF tank; DEF can be corrosive to some metals. Clean up any DEF spills immediately.
Aftertreatment maintenance
When you shut down your machine, you may occasionally notice your engine keeps running even after you turn it off with your key. This is normal. Your Tier 4 Final engine may need to continue running to cool down your exhaust system. If you’re shutting down your engine in an emergency, turn the key all the way to the left to force a shutdown. But make sure it’s an emergency, because forcing an engine shutdown can damage your aftertreatment system.
Pay attention to the Wait to Disconnect lamp on your console. Do not turn the battery disconnect switch off until this lamp goes out. The battery is needed to pump DEF out of the lines so it won’t freeze.
Always remember to refer to your machine's Operation and Maintenance Manual for more information. And reach out to your Cat dealer for any other questions about maintaining equipment.
