Why Preventative Maintenance Matters for Your Fleet
Running a fleet means keeping trucks on the road, not in the shop. But without a solid preventative maintenance plan, your vehicles can suffer from costly breakdowns, compliance issues, and reduced fuel efficiency. One of the most common and expensive failures fleets face involves the aftertreatment system, specifically the diesel particulate filter (DPF).
A failed aftertreatment system can lead to regeneration failures, clogged filters, and even engine derates, all of which put your trucks out of service and your business at risk. This guide will help you understand how to prevent aftertreatment and DPF system failures while keeping your fleet running efficiently and profitably.
Understanding the Aftertreatment and DPF Systems
The aftertreatment system in diesel trucks is designed to reduce emissions and meet EPA regulations. It consists of several key components, each with its own maintenance requirements:
1. Diesel Particulate Filter (DPF)
The DPF captures soot and other particulates from exhaust gases. Over time, these particles build up and must be burned off through a process called regeneration. If the DPF is not properly maintained, it can become clogged, leading to restricted airflow, loss of power, and engine derates.
2. Selective Catalytic Reduction (SCR) System
This system uses Diesel Exhaust Fluid (DEF) to break down harmful nitrogen oxides (NOx) into harmless water and nitrogen. A malfunctioning SCR system can cause poor emissions performance and costly fines.
3. Exhaust Gas Recirculation (EGR) System
The EGR valve recirculates exhaust gases back into the engine to lower combustion temperatures and reduce emissions. Over time, carbon buildup can lead to sticking EGR valves, reduced engine performance, and increased DPF clogging.
Top Causes of Aftertreatment and DPF Failures
1. Infrequent or Failed Regenerations
DPF filters must go through passive, active, or forced regenerations to burn off excess soot. If the regeneration process fails or is interrupted frequently, the filter can become severely clogged, leading to expensive repairs or replacements.
2. Low-Quality Fuel or Improper Additives
Using low-quality diesel fuel or incorrect oil can increase soot production, overwhelming the DPF and shortening its lifespan. Always use ultra-low sulfur diesel (ULSD) and manufacturer-approved engine oil.
3. Neglected EGR System Maintenance
A dirty or failing EGR system can send excessive soot into the DPF, causing premature clogging and filter failure. Cleaning and inspecting the EGR system regularly helps prevent unnecessary aftertreatment issues.
4. DEF Contamination or Incorrect Usage
Using contaminated, expired, or incorrect DEF fluid can lead to SCR system failures, warning lights, and costly repairs. Always store DEF properly and use the correct fluid for your truck.
5. Excessive Idling
Long periods of idling prevent the DPF from reaching the necessary temperatures for proper regeneration, leading to excess soot buildup. Encourage drivers to limit idling time and follow proper shutdown procedures.
Preventative Maintenance Strategies to Avoid Aftertreatment Failures
1. Follow a Regular Regeneration Schedule
Ensure that passive and active regenerations are completed without interruptions. If regenerations fail, a forced regen may be required at a shop. Educate drivers on how to recognize regeneration alerts and complete the process correctly.
2. Perform Routine DPF Cleanings
A DPF filter should be cleaned every 200,000 to 300,000 miles, depending on driving conditions and manufacturer recommendations. Neglecting cleanings can lead to full filter replacement, which can cost thousands of dollars.
3. Inspect and Maintain the EGR System
Schedule regular EGR valve and cooler cleanings to prevent carbon buildup. Many fleets overlook EGR maintenance, leading to higher soot output and increased DPF issues.
4. Use High-Quality DEF and Keep It Contaminant-Free
To maintain a healthy SCR system:
- Use certified DEF fluid that meets ISO 22241 standards.
- Store DEF in temperature-controlled environments to prevent degradation.
- Avoid contamination from dirt, oil, or other fluids.
5. Monitor Sensors and Warning Lights
Modern trucks come equipped with onboard diagnostics that monitor aftertreatment health. Ignoring fault codes or warning lights can lead to major system failures and expensive repairs. Train drivers to report check engine lights and DEF warnings immediately.
6. Reduce Excessive Idling
Excess idling prevents DPF regeneration from occurring naturally. Implementing idle reduction policies and using automatic engine shut-off systems can help minimize unnecessary idling time.
7. Perform Regular Oil and Fuel System Maintenance
- Change engine oil at the recommended intervals to prevent excessive soot buildup.
- Use manufacturer-approved filters to keep contaminants out of the fuel and oil systems.
- Ensure fuel injectors are clean and operating properly to reduce emissions.
The Cost of Neglecting Aftertreatment Maintenance
Failing to maintain the aftertreatment system doesn’t just lead to breakdowns—it directly impacts your bottom line. Here’s what poor maintenance can cost your fleet:
- DPF Replacement: $3,000 - $8,000
- Forced Regeneration: $300 - $1,000
- SCR System Repair: $2,000 - $5,000
- EGR System Repair: $1,500 - $4,000
- Downtime & Towing: $1,000+ per day
Investing in preventative maintenance ensures your trucks stay compliant, efficient, and profitable.
Final Thoughts: Keep Your Fleet Running with Proper Maintenance
A well-maintained aftertreatment system keeps your fleet on the road and out of the shop. By implementing routine inspections, scheduled cleanings, and proper fuel and DEF usage, you can avoid expensive failures and unexpected downtime.
Need professional assistance with DPF maintenance, forced regens, or aftertreatment repairs? Trust us at Impact Diesel Repair in Omaha, NE to look after your fleet. Schedule an appointment today!
