How to Inspect and Maintain Used Heavy Equipment

Buying a used excavator, loader, dozer, or skid steer can save a pile of money, but only if the machine doesn't turn into a money pit three months later. The ones that look shiny in pictures often hide cracked frames, tired hydraulics, or engines that have been run hard and put away wet. The trick is knowing exactly what to look for before the cash changes hands and then staying on top of it once it's on the job site.

Before Handing Over the Check

Walk-Around and Poke-Test

Start with the obvious stuff first. Grab a flashlight and crawl around. Look for fresh weld beads that weren't done at the factory – a lot of times owners patch cracks instead of fixing them right. Run a hand along booms and stick arms; if anything feels wavy or the paint is bubbled, walk away or knock a serious chunk off the price.

Check pins and bushings by having someone wiggle the bucket or blade while the machine is idling. Any clunk bigger than a light tap means worn-out joints. Tracks should have decent tread left and no missing shoes; tires need to match and not be weather-cracked to the cords.

Fluids Tell Stories

Pull every dipstick. Engine oil that looks like tar or has silver glitter in it has seen better days. Hydraulic fluid that smells burnt or looks like chocolate milk means the system has been cooking itself. Clean, honey-colored hydraulic oil is what you want to see. Coolant should be bright green or orange, not rusty brown.

Fire It Up Cold

Always try to start it before the seller has warmed it up. A machine that needs half an hour of cranking and a shot of ether is telling you the rings or injectors are tired. Once it's running, listen for rod knock, turbo whistle that isn't supposed to be there, or blow-by coming out the breather. Blue smoke on start-up usually means valve seals; constant blue or white smoke under load means it's burning oil or has injector problems.

Work the Hydraulics Hard

Run every cylinder end to end, fast and slow. Jerky movement, chattering, or a cylinder that drifts down when you hold it up points to bad spool valves or leaking cylinder packs. Lift something heavy – a full bucket of dirt or a concrete block – and hold it high for a minute. If it creeps down, budget for a reseal kit.

Dig a Test Hole or Push a Pile

Nothing hides problems like actually working the machine. Dig a trench, dump it, swing, dig again. Weak travel motors, slipping transmission clutches, or a converter that's getting hot will show up quick. Watch the gauges – if oil pressure drops when it gets warm or the temp needle climbs fast, keep negotiating.

Paperwork Reality Check

Ask for the service book. If it's a folder of random receipts or "my buddy did the oil changes," treat it like there's no history at all. Run the serial number to make sure it's not stolen or still owed on. A clean title and a stack of receipts from a reputable shop make life a lot easier.

After It's Yours

First-Week Routine

Day one on the new (to you) machine: change every filter and all fluids. Old oil and a dirty fuel filter can kill a perfectly decent engine in a hurry. Grease everything with a zerk fitting until you see fresh grease push out the joints.

Build a Simple Checklist

Hang a laminated card in the cab:

  • Every morning: walk-around, check for fresh leaks, top off fluids, look under the belly for new puddles.
  • Every 50 hours: grease, check air filter, wipe the battery terminals.
  • Every 250 hours: oil sample, new fuel filters, check track or tire pressures.
  • Every 500 hours: hydraulic filter, transmission filter, valve adjustment if it needs it.

Watch the Leaks

A drop or two of oil on a fitting isn't the end of the world, but a steady drip turns into gallons fast. Keep a roll of rags and a couple spare o-rings in the door pocket. Fix small seeps before they become gushers.

Clean It Like You're Going to Sell It Tomorrow

Mud packed in the belly pans or around radiators cooks components. A quick pressure-wash at the end of the week keeps cooling fins open and lets you spot new cracks or leaks while they're still small.

Train the Operators – Seriously

Half the wear on used iron comes from the guy in the seat. Show new operators where the load charts are, explain why slamming the bucket into the ground to clean it is a bad habit, and make sure they know never to side-load a boom. A five-minute talk can save thousands in cracked steel.

Typical Trouble Spots and Quick Fixes

ProblemWhat It Looks LikeFix Before It Gets Ugly
Hydraulic cylinder driftBucket or blade slowly dropsNew seals or packings in the cylinder
Play in pin jointsClunking when curling or dumpingTurn or replace pins and bushings
Track adjuster leakingGrease all over the idlerNew seals in the adjuster cylinder
Engine blowing blackClouds when digging hardClean or replace injectors, check air filter
Radiator cloggedTemp climbs after 20 minutesBlow it out backwards with compressed air

Keeping the Value Up

Take date-stamped pictures of major repairs. Keep every receipt in a folder. When it's time to trade or sell, a fat service file and a clean, greased machine brings way more money than one that looks like it lived in a swamp.

Bottom Line

Used heavy equipment is only a bargain if it keeps digging instead of sitting in the shop. Spend a solid half-day kicking tires and running cycles before buying, then treat it like the income producer it is afterward. Do the homework up front and stay religious about grease and filters, and that older machine can easily outlast a new payment book.

Stay safe, keep the shiny side up, and the iron will pay its way for years.