A friend from Canada sent me a very detailed inspection report for an excavator.
Honestly, it's a great job – tons of photos, every little cosmetic flaw marked, and the report was really long.
But there was one big problem: the whole thing was about how the machine looks, and almost nothing about how the machine works.
So I feel like I should explain my own inspection process and what I focus on.
First, you need to accept one basic reality: in China, about 99.9% of used excavators have been refurbished, and most of them have had the hour meter “adjusted”.
You also usually have no idea what kind of work they did before – pure dirt work, heavy rock breaking, demolition, whatever – even though that makes a huge difference to wear.
If you manage to find an excavator where the frame, swing platform, and engine serial number all match the plate and documents, then congratulations, you found a really good machine.
But usually those cost about 30% more than the “refreshed” ones.
Most of those “honest” machines are 20-ton and up, often from brands like Caterpillar and Hitachi.
Today I’m talking mainly about how to inspect refurbished machines, because that’s what dominates the secondhand market. Let's start.
1. The Identity Problem
We can’t just look at the wear on pedals, joysticks, seat, or floor mat and compare that with the hours on the meter – because most of that stuff will look brand new.
And service history? Almost never exists.
Yesterday I ran into an awkward situation:
I asked a coworker to help me take a photo of the engine serial number.
He told me most of the engine nameplates are missing, and the original plate locations are already covered in paint.
Then we tried to match the engine number and the machine serial number – and they didn’t match either.
As the refurbishing industry got more and more “creative”, this issue has just become worse.
At this point, I basically gave up trying to rely on those numbers.
So if you’re buying a “very convincing” excavator from China, my suggestion is:
assume it’s fake first, then look for the parts that are still real.
If you try to use the usual forum tips directly in the Chinese market, they’ll fail 100%.
China will show you what “manufacturing powerhouse” really means.
If you’ve ever been to a Chinese jobsite, you know almost no operator treats the machine gently.
A brand-new excavator, after one week of work, won’t look shiny anymore.
More than 2,000 hours and it will definitely be covered in scars.
And most machines are used for multiple purposes: sometimes dirt, sometimes demolition, sometimes farm work.
Every owner will squeeze as much value out of it as possible.
Also, after 2020, selling brand-new machines got harder and harder.
If someone still bought a new excavator in 2024, they must have a very good job lined up, so they’re not supposed to sell that machine right away.
That’s why any “2024 low-hour used excavator” on the market is highly suspicious.
To really know the truth about a machine, the only solid way is to compare the original invoice and registration info with the actual condition of the machine.
There’s no shortcut.
2. Checking Working Condition
My process starts by asking the seller to fire up the engine and run through a set of standard functional tests.
These include:
Starting the machine.
Smooth combined movements of boom, stick, and bucket.
Swinging clockwise and counterclockwise.
Lifting the whole machine with the boom.
Lifting the machine with the dozer blade (if it has one).
Left track forward and backward.
Right track forward and backward.
Checking if it tracks straight when moving forward and backward.
Listening to the hydraulic pump and relief noise.
Checking engine exhaust – color and consistency.
Checking for oil seepage around the swing motor and swing bearing area.
If the site allows, we should also test some real work:
Digging a small trench.
Lifting something with weight.
There’s no strict order for these actions – the point is simple:
if any movement doesn’t feel right, or there’s a strange noise, we usually don’t bother going deeper.
If a machine has already been refurbished and it still needs more repairs, that’s a big red flag.
After those tests, we let the machine sit at idle.
Only at idle can we move on to the next stage of checks.
3. Engine and hydraulic system
When it’s idling, we focus on:
Any odd knocking or irregular engine noise.
How much the machine vibrates.
The color of the exhaust: black, white, blue, or almost clear.
Roughly speaking:
Continuous white smoke: possibly coolant in the cylinder, head gasket issues, or internal water problems.
Continuous black smoke: fuel system issues, turbo problems, or poor combustion.
Blue smoke: burning engine oil, worn piston rings, or cylinder wear.
We also check oil pressure and coolant temperature:
Make sure the oil pressure warning light goes off after starting.
After running a while, see if the coolant temperature stabilizes in a reasonable range (usually around 80–95°C).
Then we feel around the hydraulic return lines and tank area to judge hydraulic oil temperature.
If hydraulic oil runs too hot, it could mean heavy internal leakage, wrong relief settings, or other system problems.
If any of these key items look suspicious, we’re ready to walk away.
4. After Shutdown
Once shut the engine down, I will check what the ground under the machine looked like before it moved.
If see oil spots, we should suspect leaks.
Then look closely at:
Engine block and oil pan.
Hose connections and fittings.
Hydraulic pump and control valve.
Cylinder ports and fittings.
Swing motor and swing bearing seals.
Most refurbished engines are cleaned up very well, so we usually can’t judge much by the color of the engine oil.
And hydraulic oil plus coolant are almost always new.
On the structure side, check:
Joints and pins for excessive play.
Pins and bushings – if they’re already loose on a “freshly refurbished” machine, that’s really bad workmanship.
Usually, the tracks, idlers, rollers, and sprockets will be replaced or “refreshed”,
and the scars on the undercarriage are often filled with putty, straightened, then repainted.
Because the undercarriage rarely completely fails, visually we can only really judge paint quality – it’s very hard to read more than that after repaint.
Look for:
Obvious patch welding.
Extra reinforcement plates.
Fish-scale welds in strange places.
But once everything is painted, a lot of that is hard to see.
we just do our best.
Smaller stuff like bucket teeth, hoses, filters will usually be replaced by new generic parts.
Even if the quality is unknown, you can normally find replacements locally later, so you needn't worry too much about those.
5. Electrical System and Cab
All warning lights and gauges.
A/C and heater.
Wipers and lights.
Wiring layout – messy or neat.
Glass, frames, and wiper arms.
Safety lockouts, seat belt, pedals, and foot rests.
If all of that looks normal, at least we know the machine is convenient and safe enough to run.
To Wrap It Up
Inspecting a refurbished excavator is very different from inspecting an original, untouched machine.
Once it’s been repainted, a lot of clues are gone.
We simply can’t rely on visual details the same way.
And honestly, AI like ChatGPT doesn’t really understand the Chinese used-machine environment,
so you won’t get truly practical, local tricks from there either.
That’s why, in my opinion, the most straightforward way is to send a “pair of eyes” to check the machine together with you over video.
Someone who knows what to look for and what’s normal or not –
for example: me.
Thanks for watching.
I’m Mike Phua.
