John Deere S680 Problems – Essential Troubleshooting
The most common John Deere S680 problems include engine cooling system clogs, sensor calibration errors (specifically ActiveYield and moisture sensors), and rotor plugging in high-moisture crops. Owners also frequently report issues with the ProDrive transmission shifting and DEF system sensor failures.
To resolve these, prioritize daily radiator cleaning, regular software updates for the CommandCenter, and ensuring the concave is properly leveled to prevent uneven wear and grain loss.
Harvest season represents the culmination of months of hard work, and your equipment must perform at its peak to ensure a profitable yield. When you are managing a large estate or a professional farming operation, the reliability of your combine is non-negotiable.
However, even the most robust machinery can encounter setbacks, and understanding common john deere s680 problems is the first step toward maintaining a seamless workflow. This guide provides the practical insights you need to diagnose and fix issues before they sideline your operation.
We will explore the mechanical, electronic, and hydraulic systems of the S680, offering expert solutions to keep your harvest moving forward. By the end of this article, you will have a clear roadmap for troubleshooting and preventive maintenance.
Engine Cooling and Power Delivery Challenges
The S680 is a powerhouse, but that power generates significant heat, especially during long days in dusty conditions. One of the most frequent complaints involves the engine overheating due to debris buildup in the cooling package.
The 13.5L PowerTech engine requires massive airflow, and the rotary screen can sometimes struggle to keep up with fine chaff. If the radiator fins become packed with dust, the engine’s thermal efficiency drops, leading to potential derating or emergency shutdowns.
Regularly inspect the fan drive belt for tension and wear, as a slipping belt will reduce cooling capacity. Use compressed air to blow out the cooling cores from the inside out every morning before starting your shift.
Diesel Exhaust Fluid (DEF) and Emissions Systems
Modern emissions standards require the use of DEF, but the sensors governing this system are notoriously sensitive. You may encounter “limp mode” errors if the DEF quality is poor or if the tank heater fails during late-season cold snaps.
Always source high-quality DEF and store it in a cool, shaded area to prevent urea crystallization. If you receive a sensor error, check the wiring harness near the DEF tank for signs of rodent damage or corrosion.
Cleaning the Diesel Particulate Filter (DPF) is also a critical maintenance task that many DIY operators overlook. Ensure the machine completes its regeneration cycles fully rather than interrupting them to save time.
Harvesting System and Rotor Efficiency
The S-Series combines are famous for their TriStream and Variable Stream rotors, which are designed for high-capacity throughput. However, rotor plugging remains a significant concern when harvesting high-moisture corn or green-stem soybeans.
When the material flow becomes restricted, the rotor drive belt can slip, causing a sudden loss of momentum. You must ensure the rotor speed and concave clearance are perfectly matched to the crop conditions of the day.
If you experience frequent plugging, inspect the concave inserts for excessive wear or bending. Leveling the concave annually is a “pro” step that ensures even threshing across the entire width of the rotor.
Managing Grain Loss and Quality
High grain loss over the cleaning shoe is often a result of improper fan speed or sieve settings rather than a mechanical failure. The S680 uses a massive cleaning area, but it requires precise calibration to balance airflow and material load.
Check the “tailings” elevator frequently to see if you are over-threshing the grain, which leads to cracked kernels and dockage at the elevator. Adjust the chaffer settings in small increments until the grain tank sample is clean and the ground is clear.
Utilize the VisionTrak system to monitor losses in real-time, but do not rely on it exclusively. Always perform a traditional “drop test” to verify that the sensors are reporting accurately for your specific cultivar.
Electronic Systems and Sensor Calibration
The S680 is a “computer on tracks,” and its electronic complexity can be a double-edged sword. Issues with the ActiveYield system and moisture sensors are common and can lead to inaccurate harvest data.
Moisture sensors can become coated with “honey” or sap from certain weeds, leading to false readings. Clean the sensor plate regularly and recalibrate the system whenever you switch between different types of grain.
Software glitches in the CommandCenter can sometimes cause erratic behavior in the AutoTrac or Header Height Control systems. Ensure your local dealer has flashed the latest firmware to the machine’s controllers before the season begins.
Wiring Harness and Connectivity Issues
Because these machines operate in harsh, vibrating environments, wiring harnesses can rub against the frame, leading to short circuits. Pay close attention to the harnesses near the hydrostatic pump and the grain tank augers.
If you experience intermittent “CAN bus” errors, it is often a sign of a loose ground wire or a corroded connector. Use an electrical contact cleaner on any plugs that appear dusty or green with oxidation.
Always secure loose wires with heavy-duty zip ties to prevent them from vibrating against sharp metal edges. This simple step can prevent hours of diagnostic headaches during a busy harvest window.
John Deere S680 Problems
When discussing john deere s680 problems, many experienced operators point toward the ProDrive transmission as a point of concern. This sophisticated system allows for seamless shifting, but it can be prone to “clunky” gear changes if the hydraulic oil is old.
The transmission relies on high-pressure hydraulic fluid to operate the clutches and the mechanical park brake. If you notice a delay in engagement, check the hydraulic filter immediately for metal shavings, which could indicate internal wear.
Another area where john deere s680 problems often surface is the unloading auger system. The vertical and horizontal augers must be perfectly synchronized to prevent “slugging” and shear bolt breakage.
Inspect the auger flighting for thinning metal, especially at the transition points where the grain moves from the tank to the discharge tube. Replacing worn flighting before it fails can prevent a catastrophic breakdown in the middle of a field.
Dealing with recurring john deere s680 problems often involves checking the moisture levels in the fuse panels located behind the operator’s seat. Ensure the cab seals are intact to prevent rainwater or cleaning spray from reaching the delicate electronics.
Transmission and Hydraulic System Longevity
The hydraulic system on the S680 powers everything from the steering to the header drive. Maintaining oil purity is the single most important factor in extending the life of these expensive components.
Change the hydraulic oil and filters according to the manufacturer’s intervals, or even more frequently if you operate in extreme heat. Use a high-quality oil that meets the JDM J20C specification to ensure proper lubrication of the wet brakes.
Listen for “whining” noises from the main hydraulic pump, which can indicate cavitation or air entering the system. Check the suction lines for cracks or loose clamps that might be drawing in air during high-load operations.
ProDrive Shifting and Brake Issues
The ProDrive system features an automatic park brake that engages when the hydro handle is in neutral. If the brake fails to release, it is often due to a faulty solenoid or a drop in charge pressure.
Calibrating the transmission controllers can often solve shifting hesitations. This process involves the software “learning” the engagement points of the clutches to provide a smoother transition between speed ranges.
Never attempt to tow an S680 without first disengaging the final drives manually. Failing to do so can result in permanent damage to the transmission and hydraulic motors, leading to a very expensive repair bill.
Proactive Maintenance and Seasonal Storage
Preventing common john deere s680 problems starts with a rigorous post-harvest inspection. Once the last acre is cut, take the time to clean the entire machine thoroughly, removing all grain and chaff that could attract rodents.
Mice and rats are notorious for chewing through wiring harnesses during the winter months. Place rodent deterrents in the cab, the engine bay, and near the fuse panels to protect your investment.
Grease all zerks until fresh grease emerges, which helps push out any moisture or dirt that accumulated during the season. This is especially important for the feederhouse bearings and the variable speed drive pulleys.
Pre-Season Inspection Checklist
Before the next season begins, perform a “shake-down” run of the machine. Engage the separator and the header at low RPMs and listen for any unusual vibrations or grinding sounds that might indicate a failing bearing.
- Check all belt tensions and look for cracks or “glazing” on the sidewalls.
- Inspect the feederhouse slats for bends and ensure the chain tension is equal on both sides.
- Verify that all lights and cameras are functional for safe nighttime operation.
- Drain any water from the fuel-water separator and replace the fuel filters.
Taking these steps ensures that you are proactive rather than reactive. A well-maintained S680 is a reliable partner that can handle thousands of bushels per hour without breaking a sweat.
Frequently Asked Questions
How do I fix a “Rotor Plugged” warning on my S680?
First, reduce your ground speed and increase the rotor RPM if the crop is tough. If it plugs completely, use the hydraulic reverser to back the material out of the feederhouse and rotor slowly. You may need to manually clear the concave if the plug is severe.
Why is my S680 losing so much grain out the back?
This is usually caused by “over-threshing” or “slugging” the cleaning shoe. Check your fan speed; if it is too high, it blows light grain out. If it is too low, the mat of chaff becomes too thick for the grain to fall through. Balance your sieve settings to the current crop weight.
What causes the “Service Engine Soon” light with a DEF error?
This is frequently caused by a faulty DEF tank heater or a clogged DEF injector nozzle. The nozzle can become encrusted with urea crystals. Removing the injector and cleaning it with warm distilled water often resolves the issue without needing new parts.
How often should I change the engine oil in an S680?
John Deere typically recommends every 500 hours if using Plus-50 II oil and high-quality filters. However, if you are operating in extremely dusty conditions or high-load environments, changing it every 250-300 hours is a safer bet for engine longevity.
Why does my ProDrive transmission shift roughly?
Rough shifting is often a symptom of air in the hydraulic lines or a need for a software recalibration. Ensure your hydraulic fluid level is correct and that the filters are clean. If the problem persists, a dealer-level calibration of the clutch engagement points is usually the fix.
Conclusion
The John Deere S680 is a pinnacle of harvesting technology, but its performance depends entirely on the care and attention it receives. By staying ahead of common john deere s680 problems like cooling clogs, sensor errors, and rotor maintenance, you can ensure a productive and stress-free harvest.
Remember that safety should always be your top priority. Never attempt to clear a plug or adjust a belt while the engine is running, and always use the safety stops on the lift cylinders when working under the header or feederhouse.
Invest in your machine during the off-season, and it will reward you with reliability when the pressure is on. Keep your filters clean, your sensors calibrated, and your cooling system clear, and your S680 will continue to be the backbone of your harvesting operation for years to come.
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