Buying a Used Hitachi 135 Excavator? Run This 7-Step Inspection Checklist

I'm a quality and compliance manager at a heavy equipment company. In practice, that means every machine that comes into our fleet crosses my desk before it goes back out to a customer—roughly 200 units a year. In 2024, I rejected about 18% of the pre-owned machines we looked at for purchase. Not because sellers were dishonest. Mostly because nobody had run a proper inspection before the machines reached our yard.

This checklist is the one I use on a used Hitachi 135 excavator. If you're adding one to a rental fleet, buying your first machine for a small contracting business, or replacing a tired unit, this is the order I'd run the inspection in. Seven steps. Most take under ten minutes. The ones that take longer are the ones that save you the most money.

Before we start: know what you're buying. The search "stork vs crane" still brings people to our site, and the joke gets old—but the serious version happens at auctions too. People show up wanting a crane and leave with an excavator, or worse, the other way around. The Hitachi 135 is an excavator. It digs, it grades, it handles attachments. It is not a lifting crane. If you need a crane, this list is the wrong tool. If you need a digger, these are the right steps.

Step 1: Verify the machine identity, not just the hour meter

Start with the serial number. The Hitachi 135 has its main plate near the cab entry, and a secondary number stamped into the track frame. Both should match the title and the bill of sale. It sounds obvious, but I've seen mismatched plates twice in the last four years. Both times, the seller had swapped components between machines and left the documentation to catch up.

The hour meter is the least trustworthy piece of data on any used machine. Here's something dealers won't tell you: hour meters on older Hitachi models are easy to replace, and a "low hours" claim is often just a claim. What I actually look at is wear on the joystick grips, the seat cushion, and the floor mat. A 2,000-hour machine and a 7,000-hour machine feel different when you climb in. Not scientific, but it tells you which way the story leans.

And don't assume low hours equal good condition. People think a machine that's been sitting is better than one that's been working. The reality is often backwards. Seals dry out, brackets corrode, and a battery that died two winters ago can be the tip of the neglect iceberg. A machine that's worked 500 hours a year, every year, is usually healthier than one that's sat for 18 months.

Step 2: Undercarriage—where the real money goes

On a compact excavator like the 135, the undercarriage is a huge slice of the total value—and it's where sellers hope you don't look closely.

What I check on every machine:

• Track bushing wear, measured with a gauge. Undercarriage manufacturers publish wear limits for each chain size; once past that mark, the chain is on its way out.
• Sprocket teeth. Hooked or pointed teeth mean the chain ran too tight, and the sprockets are likely done too.
• Idlers and rollers—flat spots and oil leaks around the seals.
• Hydraulic track tensioner. If it won't hold adjustment, that's a hidden repair bill.

A fresh wash hides all of this. I don't have hard data on how many used compact excavators are sold with worn undercarriages disguised by a pressure washer, but based on the inspections I've done over the past four years, my sense is it's well above a third in the budget price range.

Step 3: Hydraulics—leaks, drift, and tired cylinders

Warm the machine up and let the hydraulics circulate for a good ten minutes before you touch the controls. Then look.

Leaks first. A little seepage around the boom cylinders is normal life on a used machine. Active dripping is a line item. Pay attention to the hose routing near the final drive and under the boom—chafe marks and dry rot tell you more than any listing photo.

Then the cylinders. Raise the boom, hold it, and watch. A cylinder with internal bypass will drift down within a few minutes. Last year I watched a 135 hold its boom for about forty seconds before the bucket settled a foot. The seller called it "normal." We called it a replacement cylinder and priced the machine accordingly.

While you're at it, draw an oil sample from the hydraulic tank and send it for analysis. It costs about $150. It tells you if the pump is shedding metal, if water has got in, and whether that "just serviced" machine actually got serviced. Most buyers skip this step. Don't.

Step 4: Engine and electrical—don't ignore the generator

The engine in the 135 is a four-cylinder diesel with a solid reputation. Cold-start it. A little blue smoke at startup that clears within a minute is usually valve guides, which is minor. Blue or white smoke that continues once the engine is hot is a bigger deal. Black smoke under load points to injection problems.

Then the electrical side. This is where most buyers stop looking—and where I find the most creative repairs.

The charging system uses a belt-driven alternator. In Hitachi's parts catalog, that's a generator assembly, and genuine Hitachi generator parts are still widely available. That matters, because a lot of 135s repaired through the pandemic years ended up with aftermarket parts that don't match the original spec. I've pulled alternators off machines wired in with electrical tape and a non-standard pulley. The machine ran fine, right up until it didn't.

Check the wiring harness around the engine block and under the cab for rodent damage, rubbed-through insulation, and splices. A 135 with electrical gremlins is a machine that burns up someone's weekends.

Step 5: Boom, arm, and welded joints

Get the machine to ground level, bucket flat, and walk the boom and arm. I'm looking for cracked welds at the pivot points, especially where the arm meets the bucket linkage.

What most people don't realize is that a repaired weld can look fine in a photo and be structurally questionable in person. Here's what I look for:

• Cold welds—rough, ungrounded beads laid down in the field with a cheap rod.
• Heat discoloration around the original factory welds, which suggests a repair done under stress.
• Dents on the boom top. Minor dents are cosmetic. Creases across the structure are not.

Then check the pins and bushings. Grab the bucket and work it by hand. An inch of play at the pivot means bushings and pins are due. On a 135, that's a four-figure parts bill before labor.

Step 6: Run it—swing, travel, dig

If the seller won't let you operate the machine, walk away. Fifteen minutes of hands-on testing tells you more than any walkaround.

Run the swing first. The swing bearing should be smooth and quiet. A grind or a catch at the same point in rotation means it's been running short on grease. Then travel. Go straight forward and back, and turn both directions. A rhythmic knock from either side under load is a red flag inside the final drive. Final drives on a 135 are robust, but when they fail, the repair bill is outsized.

Then dig. Pick a solid bank and curl the bucket into it hard. Let the machine work against the relief valve. In a healthy 135, the hydraulics will push until the rear of the machine lifts off the ground. If it stalls early or the engine bogs before the hydraulics reach relief pressure, something is wrong in the pump or the relief circuit.

The industry has changed here, too. Five years ago you bought a used machine on a phone call and a handshake. Now you can pull telematics data and service history through Hitachi's dealer network before you even visit the machine. The fundamentals—wear, maintenance, honesty—haven't changed. But the execution has transformed, and in 2025 a buyer who doesn't use the available data is leaving money on the table.

Step 7: Paperwork, parts, and getting it home

The last step catches people off guard. Verify the title, check for liens, and confirm the machine meets emissions requirements for wherever it'll be registered.

Then sort out parts. If the machine needs work, insist on genuine Hitachi parts—or at least parts that meet the original spec. The Hitachi dealer network is global, and for a machine as common as the 135, most components ship within days. "I couldn't get the part" is not a real excuse in 2025.

And figure out the move before you bid. According to Hitachi's spec sheets (hitachicm.com), a 135-class machine runs around 13,000 to 14,500 kg depending on cab and counterweight configuration—roughly 28,000 to 32,000 lbs. That needs a proper lowboy and a truck rated for the load.

I've seen every delivery type in our yard. A box truck pulling in for a parts pickup is routine. A Denali truck or another heavy pickup hauling a mini excavator trailer is routine too. But a half-ton pickup with a gooseneck tagged to a full-size 135 is an insurance claim waiting to happen. Get the right transport before you own the machine.

What Most Buyers Get Wrong

Three mistakes come up over and over.

First, skipping the fluid analysis to save $150 on a machine that costs tens of thousands. I did exactly that once. I had two hours to make a decision before a deadline, and I waved off the oil sample. The swing drive failed three months later. That quality issue cost us a $22,000 redo and threw our fleet schedule into chaos. With the timeline pressing, I made the call with incomplete information. I regret it.

Second, trusting the photos. Listing photos always find the good side. If the listing doesn't show the track frame, the underside of the boom, or the hose routings, ask for those specific shots. If they won't provide them, that's an answer.

Third, assuming a clean machine means a good machine. A detailed wash and a coat of paint hide more than you'd expect. I'm not saying used sellers are dishonest—most are not. I'm saying the only person who loses money on a bad used machine is the one who didn't look. And that's usually the same person who skipped half this checklist.

One last consideration: this checklist comes from a fleet context, where resale value and rental dependability are always on the table. If you're a one-machine contractor, your priorities may shift. I can only speak to my own context—a mid-size B2B operation with predictable usage patterns. If you're buying a 135 for a single jobsite, the calculus might be different.