Troubleshooting Common DEF Issues in Trucks

Diesel Exhaust Fluid (DEF) is a carefully formulated solution of 32.5% high-purity urea and 67.5% deionized water, used in the Selective Catalytic Reduction (SCR) process to reduce nitrogen oxide (NOx) emissions from diesel engines. This technology is essential for meeting stringent environmental regulations, such as the EPA 2010 standards in the United States, which require significant reductions in NOx emissions.

NOx emissions are a major contributor to air pollution, causing environmental and health problems. When DEF is injected into an exhaust stream, it breaks down into ammonia and carbon dioxide, which then reacts with NOx in the SCR catalyst, converting it into harmless nitrogen and water vapor, significantly reducing NOx emissions. 

Using DEF ensures compliance with diesel emission standards, enhances the reputation of businesses, and significantly mitigates environmental impact. However, even with its benefits, DEF can sometimes cause issues in trucks if not properly handled or maintained. 

Common DEF Issues in Trucks

To keep your trucks running smoothly and efficiently, it's crucial to understand common DEF issues and how to troubleshoot and prevent them. The following covers some frequent DEF system problems and best practices for addressing them.

1. Contamination

DEF contamination can occur from poor handling practices, use of improper storage containers, or exposure to airborne contaminants.

Troubleshooting Steps:

• Drain the Contaminated DEF: Remove all contaminated DEF and replace it with fresh, high-quality DEF.
• Clean the DEF Tank and Lines: Thoroughly clean the DEF tank and lines to remove any residual contaminants.
• Replace DEF Filters: Install new filters to ensure any remaining contaminants are removed.

Preventative Measures:

• Store DEF in clean, sealed containers.
• Avoid using metal containers that can react with DEF.
• Regularly clean DEF dispensing equipment.
• Ensure that the DEF tank is capped when not in use.

2. Pump Failures

The DEF pump delivers the fluid from the tank to the injection system. Pump failures can lead to insufficient DEF flow, affecting the SCR process.

Troubleshooting Steps:

• Check Power Supply: Ensure the pump is receiving power and check for blown fuses or faulty wiring.
• Inspect for Clogs: Look for blockages in the pump or lines that might be impeding flow.
• Pump Replacement: If the pump is faulty, replace it with a new unit.

Preventative Measures:

• Regularly check the pump and lines for blockages and wear.
• Ensure the DEF is free from contaminants that could clog the pump.

3. Injector Issues

DEF injectors spray the fluid into the exhaust stream, where it mixes with the exhaust gasses. Clogged or malfunctioning injectors can disrupt this process.

Troubleshooting Steps:

• Visual Inspection: Check injectors for signs of clogging or damage.
• Flow Test: Perform a flow test to ensure the injectors are delivering the correct amount of DEF.
• Clean or Replace: Clean clogged injectors, or replace them if they’re damaged.

Preventative Measures:

• Use clean, high-quality DEF to minimize the risk of clogging.
• Regularly inspect and maintain injectors as part of routine maintenance.

Best Practices for DEF Maintenance

Even with careful storage and handling, DEF-related issues can still occur. These issues might impact the efficiency and performance of your diesel-powered trucks. 

 A long-lasting and reliable DEF system needs routine maintenance. Implement these preventative measures to help avoid common issues, maintain compliance with emission standards, and keep your fleet running smoothly.

1. Regular Inspections:

Schedule regular inspections of the DEF system components, including the tank, lines, pump, sensors, and injectors.

2. Use High-Quality DEF:

Always use high-quality DEF, such as Blue DEF, an American Petroleum Institute (API) certified diesel exhaust fluid. This product, distributed by Keller-Heart Oil, meets the highest industry standards in quality and safety to ensure optimum SCR performance. 

3. Proper Storage:

Store DEF in a clean, cool, and dry environment. Ensure DEF storage containers are sealed to prevent contamination.

4. Educate Drivers:

Educate drivers on the importance of DEF maintenance and proper handling to reduce the risk of issues.

5. Monitor Fluid Levels:

Regularly monitor DEF fluid levels, and top up as needed to ensure the system functions correctly.

Troubleshooting common DEF issues in trucks requires a proactive approach to maintenance and a keen understanding of the system's components. By following these tips and best practices, you can minimize the risk of DEF-related problems and keep your trucks running efficiently. 

For high-quality DEF products and expert advice, trust Keller-Heartt Oil–your partner in diesel engine care.