I get a lot of questions about the Komatsu 138 excavator. Maybe it's because I've been stuck in the quality end of this industry for over 4 years, reviewing specs and inspecting deliveries for a midsize heavy equipment distributor. Or maybe it's just that the 138 has this weirdly loyal following — it's an older model, but people keep asking about it.
So here's the deal. I'm gonna answer the questions I hear most often. Some of them are obvious. A couple of them are the kind you don't think to ask until after you've already made a mistake. I've made enough of those to know.
Let's start with the big one.
Is the Komatsu 138 excavator still a good machine to buy in 2025?
Yes, with one big caveat: it depends entirely on your parts pipeline. The machine itself is a solid piece of Japanese engineering — built in the late 90s to mid-2000s, typically with the Komatsu SAA4D95LE engine. Known for being reliable if maintained. The hydraulic system is straightforward, which is a blessing compared to some of the newer Tier 4 final machines that throw a code if you sneeze near the ECU.
But here's the thing I didn't think about my first time vetting one of these for a client: the 138 was discontinued years ago. That doesn't mean parts aren't available — they are, through Komatsu's aftermarket network — but it does mean you can't walk into any dealer and expect overnight delivery on every component. You need to verify your Komatsu distributor stocks the undercarriage and final drive parts for this specific model. I've seen two deals fall apart because the buyer didn't check and ended up facing 6-week lead times on a final drive motor.
Don't hold me to this, but roughly speaking, a well-maintained 138 with, say, 6,000 to 8,000 hours is still a very capable machine for medium excavation and utility work. Just make sure you've got a parts plan.
How much does a Komatsu 138 excavator cost in 2025?
I wish I had tracked auction prices more carefully over the years. What I can say anecdotally is that I've seen them range from roughly $35,000 USD for a high-hour machine needing some cosmetic work, up to about $65,000 for a low-hour unit from a reputable seller with service records.
Keep in mind that's a rough estimate. Actual pricing varies a lot depending on:
- Hours and service history (the single biggest factor)
- Undercarriage condition (replacing tracks is expensive)
- Whether it includes a thumb or quick coupler
- Your location and how far the dealer needs to haul it
One thing I learned the hard way: the cheapest 138 for sale is often the most expensive in the long run. I reviewed a batch of machines for a client in 2023 where the lowest-priced unit had visible wear on the swing bearing. The repair cost would've eaten the savings. That 'budget choice' looked smart until we got the inspection report. Net loss? About $4,000 in extra transport and teardown fees they wouldn't get back.
What are the most common problems with the Komatsu 138?
In my experience reviewing these machines — and I've looked at somewhere around 30-40 units over the last few years — the most common issues fall into three categories:
- Undercarriage wear. This is true of any excavator, but the 138 is heavy enough that neglected track chains and sprockets can get ugly fast. I've rejected two machines specifically because the track tension was so far off it had worn the sprockets into a shark-fin shape. Normal tolerance would be some wear, but these were beyond spec.
- Hydraulic hose leaks. Age is the enemy here. The 138 uses a lot of hoses, and on a 20-year-old machine, dry rot is common. It's not a dealbreaker — it's maintenance — but it's a negotiating point.
- Final drive noise. The final drive motors on these can develop whining or grinding over time. If you hear it during a test, that's not a 'maybe later' problem. That's a $2,500-$4,000 rebuild waiting to happen.
It's tempting to think you can just inspect the exterior and call it good. But the spec sheet doesn't tell you about the internal wear. I always recommend a third-party inspection for any used heavy equipment purchase. Costs maybe $400-600. Saves you from buying a machine that looks pristine but has a failing hydraulic pump.
Can you still get parts for a Komatsu 138 excavator?
Short answer: yes. Long answer: it depends on which parts and where you are. Komatsu's aftermarket parts network is genuinely one of their strongest advantages as a brand. For common wear items like filters, seals, and undercarriage components, you're usually fine. I can typically source those through a Komatsu distributor or a specialized aftermarket supplier within a week or two.
Where it gets tricky is with electronic components (if the machine has them) or specific hydraulic pump parts for the early models. Those might require cross-referencing part numbers or sourcing from a salvage yard. I've seen a distributor in Texas keep a surprising inventory of 138 parts, while a dealer in the Pacific Northwest told me flat out they don't stock anything for that model anymore.
Take this with a grain of salt: if you're buying a 138, call your local distributor before you buy and ask about lead times on a final drive motor and a hydraulic pump. If they say 'in stock,' you're golden. If they say 'special order, 4-6 weeks,' factor that into your price negotiation.
Komatsu 138 vs. newer excavators — is the older one really better?
I hear this a lot. 'They don't make 'em like they used to.' And that's sort of true, but it's also an oversimplification.
The Komatsu 138 is simpler. Fewer electronics. Less to go wrong with the emissions system. The engine is mechanically injected — no common rail, no DPF, no DEF fluid. For a contractor who wants a machine that will start every morning without sensor drama, that's a real advantage.
But the 'newer machines are worse' argument ignores a few things. Newer models are more fuel-efficient. They're quieter in the cab. They have better ergonomics. And they typically have more breakout force and faster cycle times thanks to hydraulic system improvements.
A blind comparison: same job site, same operator, same bucket. The newer machine finishes faster and uses less fuel. But it costs more to buy and more to repair when the electronics fail. The 138 costs less upfront and is easier to fix yourself, but you'll be fixing it more often. There's no universal 'better' — it's a trade-off.
I'd argue the 138 makes sense if you're a smaller contractor who does your own maintenance and can't justify a $120,000+ payment on a new machine. If you're running a fleet with a maintenance shop, the newer model might actually be cheaper per hour over its life. It depends on your specific cost structure.
How many hours is too many on a Komatsu 138?
I'm not 100% sure there's a hard number, because maintenance history matters more than hours. But from my experience reviewing machines, I get nervous above 10,000 hours unless there's documented major work — especially engine rebuild or hydraulic pump replacement.
A 138 with 8,000 hours that's been serviced on schedule? I'd look at it seriously. A 138 with 6,000 hours that's been run by three different owners with no service records? That's a gamble I wouldn't take again. We had a machine come through once with 5,400 hours on the meter, looked clean. Turned out the meter had been replaced. The engine had over 9,000 hours of hard work. That assumption — 'low hours means low wear' — cost someone a lot of money.
Roughly speaking, I'd say 8,000 hours is the sweet spot for price vs. remaining life. Above 10,000, you're buying a project, not a tool.
Where should I look for a Komatsu 138 excavator for sale?
You've got options. Online marketplaces, dealer trade-ins, auctions. In my experience, the most reliable route is through an authorized Komatsu distributor that handles used equipment. They're not always the cheapest, but they have incentive to stand behind what they sell — future parts business, reputation, that kind of thing.
Auctions can be cheaper, but you're buying with limited inspection time. I've seen great machines go for 20% below market at auction, and I've seen junkers with hidden frame cracks sell to optimistic bidders. If you go that route, bring someone who knows what to look for.
And one thing I always tell people: don't ignore the smaller regional dealers. A lot of the high-volume online listings get picked over fast. A dealer in a rural area might have a 138 sitting on their lot that hasn't even made it to the website yet. It's worth making a few phone calls.
I don't have hard data on which channel gives you the best price. But based on five years of watching deals close (and fail to close), the buyers who do their homework — checking parts availability, getting an inspection, knowing the real value — always end up happier than the ones who just click 'buy now' because the listing photos looked good.
