Common Issues with Peterbilt Model 579 and How to Fix Them

The Peterbilt Model 579 is a popular and well-regarded semi-truck known for its fuel efficiency, driver comfort features, and advanced technology. However, like any complex machine, it can experience issues over its operational lifetime.

Continue reading below fore a comprehensive overview of common problems you might encounter with your Peterbilt Model 579 as well as practical solutions for truck owners, fleet managers, and mechanics.

Typical Engine Issues And How We Fix Them

The engine is key to any heavy duty truck, including the Peterbilt Model 579. The PACCAR MX-13 engine used in this model is reliable but can still face issues:

EGR (Exhaust Gas Recirculation) System Problems

• Cause: EGR coolers or valves can get clogged, hurting engine performance and increasing fuel use.
• Fix: Clean the EGR system regularly and replace bad parts. Sometimes an EGR delete kit is used but may affect emissions rules.

DPF (Diesel Particulate Filter) Blockages

• Cause: Soot buildup in the DPF lowers engine power and triggers warning lights.
• Fix: Make sure regular regeneration cycles happen. If problems continue, forced cleaning or professional service (like as those offered by us at Mac’s Diesel and Trailer Repair!) may be needed.

Turbocharger Issues

• Cause: Worn parts inside the turbo can reduce power and increase oil use.
• Fix: Change oil regularly using the right type. If damaged, rebuild or replace the turbocharger.

Oil Leaks

• Cause: Seals and gaskets wear out over time causing leaks.
• Fix: Check for leaks often and replace worn seals quickly to avoid bigger engine damage.

Coolant Leaks

• Cause: Leaking coolant can cause overheating and engine damage.
• Fix: Regularly check coolant levels and look for leaks. Replace damaged hoses, gaskets, or water pumps as needed.

Electrical System Problems

The Peterbilt Model 579 depends on a healthy electrical system to run right. Electrical problems like battery drain, alternator failure, starter motor issues, faulty sensors, wiring harness damage, and dashboard electronic failures are not foreign to our expert mechanics when getting calls about these trucks.

By fixing these common electrical problems quickly, truck owners and fleet operators can keep their trucks running well and reliable. Regular checks and maintenance help catch issues early and avoid expensive repairs later, so if you are experiencing any of these problems mentioned so far, give us a call today at (859) 433-4062 and let our pros get things situated correctly.

Transmission and Drivetrain Issues

The transmission and drivetrain are important parts of the Peterbilt Model 579 that send power from the engine to the wheels. Below are some common problems and how we fix them:

1. Transmission Fluid Leaks

• Problem: Losing transmission fluid can cause poor shifting and damage the transmission.
• Fix: Check regularly for leaks around seals and gaskets. Replace worn seals and keep fluid levels correct.

2. Clutch Wear

• Problem: In manual transmissions, a worn clutch can slip or make it hard to change gears.
• Fix: Adjust the clutch if possible. If it’s very worn, replace the clutch. Driving carefully helps the clutch last longer.

3. Shift Solenoid Problems

• Problem: In automatic transmissions, bad shift solenoids can cause rough or failed gear changes.
• Fix: Use diagnostic tools to find faulty solenoids and replace them as needed.

4. Driveshaft Vibrations

• Problem: Worn U-joints or an unbalanced driveshaft can cause vibrations and extra wear on parts.
• Fix: Check and replace worn U-joints. Balance the driveshaft if needed.

5. Differential Problems

• Problem: Worn bearings or gears in the differential can make noise and lead to failure.
• Fix: Change differential fluid regularly to avoid problems. Repair or replace the differential if issues arise.

6. Electronic Control Module (ECM) Issues

• Problem: In automated manual transmissions, ECM faults can cause shifting problems.
• Fix: Use diagnostic tools to find ECM faults. Update software or replace the ECM if needed.

Suspension and Steering Problems

The suspension and steering systems are important for a smooth ride, good handling, and safety. We’ve outlined the most frequent reasons truck owners give us a call about these parts of their Peterbilt Model 579 they they need professional help with:

Air Suspension Leaks

• Problem: Air leaks in the suspension can cause uneven ride height and poor handling. Use air suspension leak detection and repair methods to find and fix these leaks.
• Fix: Check air lines, bags, and fittings for leaks. Replace any damaged parts and keep the air pressure correct.

Worn Shock Absorbers

• Problem: Old shock absorbers can make the ride rougher and wear out tires faster. Learn about the effects of worn shock absorbers on ride quality to spot this issue early.
• Fix: Regularly check shocks for leaks or damage. Replace them in pairs if needed.

Steering Alignment Problems

• Problem: Misaligned steering causes uneven tire wear and poor handling. This shows why steering alignment matters for tire life.
• Fix: Get regular alignment checks, especially after hitting potholes or curbs. Adjust alignment as needed.

Worn Kingpins and Tie Rods

• Problem: Worn kingpins or tie rods can cause loose steering and uneven tire wear. Know the signs of kingpin and tie rod wear and when to replace them to keep steering safe.
• Fix: Check for too much play during inspections. Replace worn parts quickly to avoid more damage.

Power Steering Pump Problems

• Problem: A failing power steering pump makes steering hard or noisy. Watch for early signs of power steering pump failure to prevent bigger issues.
• Fix: Regularly check power steering fluid levels and condition. Replace the pump if it’s failing.

Leaf Spring Wear

• Problem: Leaf springs can sag or crack over time, affecting ride height and comfort. Look for leaf spring wear signs and replacement advice during checks.
• Fix: Inspect leaf springs for damage or wear. Replace worn springs, possibly with stronger materials for better durability.

Wheel Bearing Problems

• Problem: Worn wheel bearings cause noise, vibration, and risk wheel separation. Regular wheel bearing care for trucks helps prevent this.
• Fix: Grease and inspect wheel bearings regularly. Replace them at the first sign of wear or noise.

By fixing these transmission, drivetrain, suspension, and steering problems quickly, truck owners and fleet operators can keep their trucks running well, safely, and efficiently.

As an expert semi truck repair services provider, we cannot stress enough that regular maintenance and checks can help catch these issues early on, saving money on repairs and avoiding downtime.

Brake System Problems

With brakes at the helm of the safety of both the truck driver and everyone else on the road, there are plenty of common brake problems that should be paid attention to and, again, how we go about correcting them:

Air Brake System Leaks

• Problem: Air leaks can make brakes less effective and may cause the system to fail.
• Fix: Regularly check air lines, fittings, and brake chambers for leaks. Replace any damaged parts and keep the air pressure at the right level.

Brake Pad and Rotor Wear

• Problem: Worn-out brake pads and rotors can reduce braking power.
• Fix: Check brake pads and rotors often. Replace pads when they get too thin, and resurface or replace rotors if needed.

ABS (Anti-lock Braking System) Problems

• Problem: ABS failures can lower braking performance, especially in emergencies.
• Fix: Take ABS warning lights seriously. Use diagnostic tools to find the problem and replace faulty sensors or modules as needed.

Brake Adjustment Issues

• Problem: Brakes that aren’t adjusted properly can cause uneven braking and longer stopping distances.
• Fix: Regularly check and adjust the brake stroke. Consider adding automatic brake adjusters if your truck doesn’t have them.

Air Dryer Problems

• Problem: A broken air dryer can let moisture into the air system, causing rust and valve problems.
• Fix: Change the air dryer’s desiccant cartridge as recommended. If issues continue, you might need to replace the whole air dryer.

Cabin Comfort and Amenity Issues

Whether or not these issues wouldn’t make the cut for your list of emergency repairs, a comfortable driver’s cabin is important for long trips. Both your awareness of activity on the road and mental clarity while maneuvering a big rig are essentially affected by these common problems:

HVAC System Problems

• Problem: Poor heating or cooling makes driving uncomfortable.
• Fix: Regularly service the HVAC system by cleaning or replacing filters, checking refrigerant, and making sure fans and controls work well. Keep your truck’s HVAC in good shape for best results.

Seat Comfort Issues

• Problem: Old or broken seats cause tiredness and discomfort.
• Fix: Check seat suspension often. Replace worn cushions or seats if needed to improve comfort.

Noise and Vibration

• Problem: Too much noise or shaking causes fatigue and stress.
• Fix: Find the source like loose panels or worn engine mounts. Repair or add insulation to reduce noise and vibration.

Electronics Not Working Properly

• Problem: Issues with infotainment, GPS, or other electronics affect comfort and efficiency.
• Fix: Keep software updated. For hardware problems, get help from a Peterbilt specialist. Use troubleshooting tips to fix electronic issues quickly.

Sleeper Berth Problems

• Problem: Issues with the sleeper berth affect rest and recovery.
• Fix: Regularly check the mattress, curtains, and storage. Replace worn parts to keep the sleeper comfortable.

Preventive Maintenance Tips

One of the most effective ways to keep these problems from becoming problems in the first place is to schedule regular preventative maintenance services with your local heavy duty truck repair shop. (If you’re in the Lexington, KY, area, give us a call!)

Check out our recommended lineup of maintenance checks and services that would be beneficial to add to your routine processes, whether you are driving long hauls for income, or running a fleet of trucks:

1. Follow Service Schedules: Stick to Peterbilt’s recommended times for oil changes, filter swaps, and routine checks.
2. Do Regular Inspections: Check your truck daily before trips and do detailed weekly inspections to catch problems early.
3. Watch Fluid Levels and Quality: Check engine oil, coolant, transmission fluid, and others regularly. Change fluids as recommended.
4. Keep Detailed Records: Write down all maintenance work, repairs, and part changes.
5. Fix Small Problems Quickly: Tackle minor issues before they become bigger and cost more to fix.
6. Use Quality Parts: When replacing parts, use high-quality OEM or approved parts for reliability.
7. Train Drivers on Best Practices: Teach drivers how to operate the truck properly, including shifting, braking, and spotting potential problems.
8. Use Onboard Diagnostics: Regularly download and check data from the truck’s diagnostic system to find issues early.

Choose Mac’s Diesel and Trailer Repair For Your Peterbilt Problems

Hands down, the Peterbilt Model 579 is a strong and reliable truck! But a truck it is, and it needs proper maintenance to perform at its best.

Knowing these common problems and how we handle them helps owners keep their trucks running longer, save money, and have safer, more comfortable drives. Ready to make a call to pro heavy duty diesel mechanics like ours to give you peace of mind and increase your truck’s efficiency? Give us a call at Mac’s Diesel and Trailer Repair today at (859) 433-4062 and let us know what problems you’re facing, and, being a mobile repair service provider, will meet you where you’re at to make the repairs! You’ll be glad you did.

This post was originally published on 9/6/2024 and updated on 2/12/2026 for accuracy and a larger scope of information.