A guy brought his combine into the shop last week, smoke pouring from the engine bay. He'd been running it hard through wheat harvest, skipping the daily greasing because he was in a rush. That kind of story is all too common. When you're racing against weather, it's easy to let maintenance slide. But I've learned over forty years of turning wrenches that skipping a five-minute job can cost you a full day of downtime or worse. My grandfather taught me this trick: take care of the machine, and it'll take care of you. Combine maintenance doesn't have to be complicated, but it does have to be consistent. Here's what I tell my customers who run combines.
Start with a Clean Machine
The number one enemy of a combine is dirt and debris. After every day of harvesting, blow out the engine compartment, radiator, and separator area. I use a leaf blower or compressed air. If you let chaff build up, you're asking for overheating and even fires. My grandfather used to say, "Clean machine keeps the harvest green." Make it a habit. Spend ten minutes after each day, and you'll save hours of troubleshooting later.
Don't Skip the Little Things
Combine maintenance is about attention to detail. Check the belts, chains, and bearings daily. Look for frayed belts, loose chains, and hot bearings. I use a infrared thermometer to check bearing temps on the header and elevator. If one's running 20 degrees hotter than the others, it's time to grease it or replace it. Also, change the engine oil and filters per the manual, not when you remember. A combine works hard in dusty conditions, so use a good diesel oil and change the air filter when the restriction indicator says so. A clogged air filter robs power and wastes fuel.
Keep Your Belts and Chains Tight
Loose belts slip and wear out fast. Loose chains can jump sprockets and cause major damage. I check tension every morning before starting. For belts, I use the twist test: if you can twist the belt more than 90 degrees on the longest span, it's too loose. For chains, there should be about half an inch of slack per foot of span. Lubricate chains with a good penetrating oil, not WD-40. I like a chain lube that doesn't fling off. Shop Trick: mark your belt and chain tensioners with a paint marker so you can see at a glance if they've moved.
Check Your Hydraulics
Hydraulics run the header, reel, and unloading auger. Leaks can cause slow operation or complete failure. Inspect hoses for cracks and chafing, especially where they rub against each other. Replace any hose that looks suspect. Also, check the hydraulic fluid level and condition. Milky fluid means water contamination—drain and refill. I always keep a spare set of hoses for the most common sizes on the combine. When a hose blows in the field, you're not going to the parts store until tomorrow. Be prepared.
Know When to Call a Pro
Some jobs are beyond what you can do in the field. If you've got a major engine issue, transmission problem, or electronic fault that you can't diagnose, bring it to a shop. I've had farmers try to rebuild a hydraulic pump themselves only to damage the gearbox. Combine maintenance is one thing, but major repairs need the right tools and training. No shame in calling a pro. That's what we're here for.
Conclusion
Combine maintenance doesn't have to be a headache. Stick to a daily routine: clean it, grease it, check belts and chains, and watch your fluids. These simple steps will keep your combine running through the whole harvest. My grandfather taught me that a well-maintained machine is a happy machine. Keep that in mind next time you're tempted to skip the morning check. It'll pay off in fewer breakdowns and a cleaner harvest.
Prepare for Off-Season Storage
When harvest is over, don't just park your combine in the shed and walk away. Proper off-season storage can extend the life of your machine by years. Start by giving it a thorough cleaning inside and out. Remove any leftover grain from the grain tank, augers, and elevator. Grain left to rot attracts rodents and moisture. Next, change the engine oil and filter to prevent acidic oil from sitting in the engine. Also, drain and replace the coolant if it's due. Top off the fuel tank and add a biocide to prevent algae growth. If you live in a cold climate, check the antifreeze protection level. Lubricate all grease fittings one last time. Cover the exhaust pipe with a plastic bag to keep out moisture. Remove the battery and store it in a cool, dry place on a trickle charger. Inspect belts for cracks and replace any that are worn—it's easier to do in the shop than in the field next year. Finally, block the combine up off the tires to prevent flat spots. I've seen combines that were stored properly come out in spring ready to go, while neglected ones need weeks of repair. A little effort now saves big headaches later. Follow this combine maintenance checklist before you walk away for the season.
