Hey there, I’m Jake, and for the last 12 years, I’ve been the go-to guy for used excavators out here in the Southeast. I’ve sat on more jobsites than I can count, watched machines beat the crap out of their engines over tight deadlines, and fixed more overheating excavators than I can remember. The worst part? Most of the time, this stuff happens to used machines—guys think because they didn’t buy brand new, they have to skip the little checks that keep their excavator from turning into a steaming hunk of metal mid-job. If you’re picking up a used excavator from my lot, or anywhere else, let me save you the headache of a mid-project breakdown. Overheating isn’t some random glitch—it’s usually avoidable with a few simple, regular moves. Let’s break this down like we’re talking over a coffee at the shop, no fancy jargon required. Used Excavator
First off, let’s get one thing straight: used excavators don’t overheat because they’re “old.” They overheat because their owners skip the basic maintenance that new machine owners get handed on a silver platter. I’ve got a 2018 Kubota on my lot that ran 10 hours straight last week without a blip, and a 2022 model sitting across the yard that’s been in three times this month for overheating—turns out the new owner forgot to check the coolant level. Let’s start with the most obvious, most overlooked step: checking your cooling system before you even fire up the machine that first time, and every single day after that. I see guys show up to a job, drop the excavator, and immediately start digging without lifting the hood. That’s a fast track to trouble.
Coolant is the blood of your excavator’s cooling system—just like blood needs the right mix, coolant isn’t just water. A lot of used machine owners mix water and old coolant, or even straight water, because they think “it’ll do for a quick dig.” Newsflash: water boils at 212°F, but your excavator’s engine runs at around 195-220°F—so straight water will turn to steam before the engine even hits its sweet spot. Good coolant, the kind I fill every used machine with before it leaves my lot, has corrosion inhibitors that keep the radiator and engine block from rusting, and a higher boiling point (usually around 260°F for standard stuff, even more for heavy-duty). Here’s the trick: don’t just check the overflow tank—open the radiator cap (wait till the engine is totally cold, by the way—steam will burn the shit out of you) and make sure the level is up to the line. If it’s low, top it off with the right coolant for your machine, not that cheap blue stuff from the gas station. Most excavators use ethylene glycol-based coolant, but some newer models use organic acid tech—ask me, or your mechanic, if you’re not sure, don’t guess. And if you see any gunk in the coolant, that’s a red flag—rust, oil mixing in, that means you’ve got a leak or a bad head gasket, and ignoring that will lead to a melt-down for sure.
Next up, the radiator—this thing is like the lungs of your excavator, and if it’s clogged, your machine can’t breathe. Used machines, especially the ones working in dirt, mud, or dust (which is basically every jobsite), get their radiator fins packed full of crud. I had a guy bring in a 2019 Cat last month; he’d been digging around a gravel pit for three weeks without checking the radiator. When I lifted the hood, the fins were so packed with dust and fine gravel you couldn’t see the metal. No wonder it overheated every afternoon—air couldn’t get through to cool the coolant. The fix? You don’t need a fancy pressure washer (though a gentle one works, just don’t blast the fins too hard or you’ll bend them). Every single day, before you start work, take a soft brush or even an air compressor on low pressure and knock off the loose crud from the front of the radiator. If it’s really packed, pop the radiator grill off and get in between the fins—pay attention to the sides and the bottom, that’s where crud hides. I always tell my customers at the lot: if you’re working in dusty conditions, do this twice a day, not once. I’ve seen guys save $10k on a new radiator just by spending 5 minutes a day brushing off fins.
Another big one that people sleep on: checking the water pump and the thermostat. The water pump moves the coolant through the engine and radiator—if the impeller is worn, or the belt is slipping, coolant isn’t flowing like it should, and boom, overheating. For used excavators, especially ones with 5,000+ hours on them, the water pump’s bearings can wear out, the belt can crack or stretch so much it slips. How do you check this? Every 250 hours, or whenever you change the coolant, inspect the belt. It should have about half an inch of give when you press on it—any more, it’s too loose, and you need to adjust or replace it. And if you hear a squeal when you start the machine, that’s the belt slipping, don’t ignore it. As for the thermostat—this little valve controls when coolant flows to the radiator. If it’s stuck closed, coolant can’t circulate, and overheating happens fast. A lot of guys will replace the thermostat when they do coolant, and it’s a cheap part—like $30-$50 for most excavators. I throw a new thermostat in every used machine I prep for sale, because it’s a $50 part that avoids a $2,000 repair.
Now, let’s talk about how you operate the machine—this is where a lot of new used excavator owners mess up, especially if they’re coming from a smaller machine. Used excavators are built for consistent work, not hammering the throttle all day. I see guys hop into a 10-ton excavator, put it in full throttle, dig a 10-foot deep hole in 20 minutes, and wonder why the engine is steaming 2 hours later. That’s called “lugging” the engine, and it’s a huge cause of overheating. When you push the excavator harder than it’s built for—like lifting a load that’s too heavy, or digging through rock without breaking it up first—your engine has to work way harder, which makes it run hotter. Here’s the rule: keep your throttle at the recommended setting. Most excavators have a “standard” throttle and a “high” throttle for heavy loads. Use the standard setting for most digging, only kick it up when you need extra power for lifting really heavy stuff. Also, don’t let your machine idle for hours on end. A lot of guys will start their excavator in the morning, go get coffee, and leave it idling for 2 or 3 hours before they start work. Idling means the engine is running, but there’s not enough load to warm up the coolant properly, and the radiator isn’t moving enough air to cool it. If you have to idle, keep the throttle at a low, not idle, setting, and move the machine a little every 10 minutes to get some airflow going.
Wait, and let’s not forget about the hydraulic system—wait, some people mix up engine overheating with hydraulic overheating, but they’re linked. If your hydraulic system is working harder than it should, it puts extra strain on the engine, which makes the engine coolant run hotter. A clogged hydraulic filter, or hydraulic fluid that’s old and dirty, can make the hydraulic pump work overtime, which leads to engine heat. So changing your hydraulic fluid every 1,000 hours (or whatever the machine’s manual says) isn’t just for the hydraulics—it’s for preventing overheating. I always set a reminder for my customers at the lot to do that, because skipping fluid changes on a used machine is a one-way ticket to overheating town.
Now, what do you do if your excavator does start overheating mid-job? I’ve seen guys panic, yank the throttle all the way, and shut it off right away— that’s bad. If you shut off a hot engine right away, the coolant that’s still in the engine can boil, and the pressure can blow hoses or crack the engine block. Instead, ease off the throttle, put the excavator in neutral, and let it idle for 5-10 minutes. Once the temp gauge starts to drop, you can shut it off. If you’re stuck in the middle of a jobsite, pull over to a shaded spot (if you’re lucky enough to have shade) and keep the engine idling, then check the radiator. If it’s packed with crud, brush it off while it’s idling—don’t open the radiator cap until it’s totally cold, though. And if the temp is spiking and staying high, don’t keep running the machine—you’ll blow the engine, and that’s a $20,000 mistake, easy.
Let me be real with you—when you buy a used excavator from me, I don’t just toss you the keys and say “good luck.” Every machine on my lot gets a full pre-delivery inspection, including checking the cooling system, changing the coolant, cleaning the radiator fins, and replacing worn belts and thermostats. But that’s just the start. The number one reason my customers come back (or send their friends) is because I don’t just sell machines—I tell them the truth, even the boring maintenance stuff that keeps their machine running. I’ve had a customer from Atlanta call me last month, panicking because his new-to-him Cat was overheating on a foundation dig. He said he’d checked the coolant but didn’t think to clean the radiator. I told him to pull the machine to the side, grab a brush, and knock off the dust. He did it, and his temp dropped 20 degrees in 10 minutes. That’s the stuff no YouTube tutorial will tell you—you don’t need expensive parts, you just need to pay attention to the small shit.
Another thing I’ve learned over the years: don’t wait for the temp gauge to light up like a Christmas tree. Most excavators have a warning light that comes on before the engine gets too hot—pay attention to that. If the light flickers, or the temp needle creeps up past the middle, that’s your signal to check the radiator, ease off the throttle, not keep pushing. I had a guy in Charlotte last year who ignored that light, kept digging, and ended up with a cracked engine block. He spent $15,000 on a new engine, and it all could’ve been avoided by stopping for 10 minutes when the light first came on. Used machines have more hours, more wear, so they’re more prone to little issues showing up early—don’t brush off the early signs.
And let’s talk about a common mistake with used excavators: the owner doesn’t have the operator trained. A lot of guys will hire a operator who’s never run that specific machine, or a operator who’s used to beating on smaller machines. I’ve had customers tell me “my operator knows what he’s doing” and then I watch him run a used excavator like it’s a mini-excavator, full throttle all day. That’s not good—operators need to know how to handle the machine, how to adjust throttle, how to spot when the temp is spiking. I always tell my customers to make sure their operator gets a quick run-through on the cooling system basics before they start work, because even a good operator can make a mistake if they don’t know the machine’s quirks.
Now, before you go—if you’re in the market for a used excavator, don’t let overheating scare you. Every used machine has quirks, but with the right checks, it’s avoidable. I’ve got machines on my lot from 2016 to 2023, all serviced regularly, all run smooth. If you have questions about a machine, or want to pick up a used excavator that’s been prepped right, hit me up. I’m not a sales guy who’ll pressure you— I’ll tell you if a machine is a good fit, or if you need something else. Just reach out, and we can work out a deal that works for your jobs.
At the end of the day, used excavators aren’t like new cars—they’re workhorses, built to get dirty and dig hard. But they still need care. Skip the daily checks, ignore the temp light, mix water and coolant, and you’ll end up stranded on a jobsite with a steaming hunk of metal. Do the little stuff: check coolant daily, clean the radiator, replace old belts and thermostats, run the machine right, and your used excavator will run for thousands more hours. I’ve seen it happen a hundred times, and I’ll keep telling anyone who’ll listen—maintenance isn’t a hassle, it’s how you keep your machine working for you, not against you.
Side Board Semi Trailer References:
- Caterpillar Inc. (2021). Operation and Maintenance Manual for 320 Excavator.
- Deere & Company (2020). Cooling System Care Guidelines for Medium Excavators.
- Construction Equipment Association. (2022). Best Practices for Used Heavy Machinery Maintenance.
- Kubota Tractor Corporation. (2019). Used Excavator Pre-Delivery Inspection Checklist.
- Society of Automotive Engineers. (2021). Hydraulic and Engine Cooling System Compatibility for Off-Road Equipment.
Heavy Leading Company Limited
Heavy Leading Company Limited is one of the most experienced used excavator manufacturers and suppliers in China, featured by quality products and low price. Welcome to buy discount used excavator in stock here and get pricelist from our factory. We also accept customized orders.
Address: Guotang, Quanpu, Liangshang, Jining City, China
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