1. Tires: Check and measure all four tires. Unless a tire has been retreaded, check for tread wear by using a tire measuring tool. Refer to the guide published by the tire manufacturer to find new tire tread depth, and make a comparison to determine remaining tread depth.

2. Brakes/axles: On dry disc brakes, look at the shape of the wear plates to make sure the brakes havent been run without them. On axles, get under the machine to determine if the oscillation bushing is out or worn, noticeable by a space at the top and bottom of the bushing.

3. Center pin (articulation joint): While another person operates the machine, look for up-and-down movement in the top and bottom center pins, which could indicate wear.

4. Frame: Inspect the frame for cracks, taking note of these problem areas: steering cylinder pin, bellcrank and where the front axle is bolted on the frame. Also look for rust.

5. Coupler/bucket: Look for wear on the bucket sides and cutting edge. Make sure the bottom wear plates dont have excessive wear. Also, check for welds or cracks.

6. Linkage: Working with another person who operates the machine, check for excessive sideways movement in all the pin areas: boom, tilt cylinder, tilt rod end, boom cylinder, lift rod ends, tilt link pins, top bucket, bottom bucket and bellcrank.

7. Engine: Look for oil leaks and water leaking under the head. Check the oil for traces of water or antifreeze. Pull out both air filters for evidence of dirt. Find out whether its ever been rebuilt, replaced or had major repairs, and who did the work. Watch for excessive smoke and listen for unusual noises.

8. Cab: Record the machine hours, and check whether all the little things work: all gauges, levers, windshield wipers, switches, heating and air conditioning. Is the seat torn? Does it move easily? Do all doors and windows open and shut? Are all electronics in working order? Make sure the oil pressure light goes out. Also, check service and parking brake.

9. Cooling system: Examine the radiator cooler core to make sure its damage-free. See if any of the individual radiator tubes have been damaged; you may have to have the radiator re-cored. Also check for leaks. If the machine is air-conditioned, make sure the compressor is in working order. Never open a radiator if it feels warm.

1. Bucket: Make sure the bucket is the right size and type for your intended applications. Check for dents, damage, cracks or welds.

2. Pins and Bushings: On the dipper and bucket pins and bushings, look for signs of regular greasing.

3. Boom and Stick: Check for structural damage, cracks or welds on the boom and stick.

4. Hydraulic Cylinders: Hydraulic cylinders should be smooth and blemish- free. Presence of oil indicates a scratched cylinder or the need for new packing inside the cylinder housing.

5. Pins and Bushings: The boom arm pins and bushings should show evidence of regular greasing.

6. Front Idler: The front idler should have some room left to extend forward on the track frame.

7. Roller and Pin Clearance: Check clearance between the bottom of the guide rollers and the top of the track pins.

8. Roller Frame: Inspect roller frame for cracks or welds.

9. Pins and Bushings: Pins and bushings loosen up over time, causing the tracks to sag.

10. Final Drive: Inspect final drive and sprocket for wear or leaks.

11. Ring gear and Turntable: Check the ring gear and turntable for deflection. Rotate the cab and boom arm to detect any hesitation or roughness.

12. Engine: Open the service access doors and inspect the engine, dipsticks and sight gauges. Check the hydraulic pump, hoses and valve bank for leaks.

13. Cab: Inspect the overall condition of the cab. Note any broken or cracked glass, dented sheet metal or structural rust.

1. Tires: Make sure all tires are the correct size. Measure and record tread depth for each one. Examine treads and sidewalls for tears and other damage. Remember to check the inner sidewalls as well. Also, look at the inside of all wheels for leaking axle seals.

2. Rear: With the bed raised and safety bar engaged, check the rear frame, bed hinge pins, wear pads, differential and driveshaft for any distorted areas, cracks or welds. Also examine the underside of the bed and the emergency and parking brake systems.

3. Dump Cylinders: The dump cylinders are exposed and can be damaged during loading operations. They should be closely checked for impact damage.

4. Articulation: The articulation joint and steering cylinders must be examined closely. Watch for excessive play in the components as they move through their normal range of motion.

5. Cab Rear: There are several important components mounted on the back of the cab, including hydraulic fluid sight glasses. The steering accumulator and transmission pump are also located here and should be checked for leaks.

6. Engine: Engine inspection should include a check of all fluid levels. Also note the condition of all belts and hoses as well as the radiator and exhaust system. Keep an eye out for excessive oil leaks.

7. Cab: Inspect the overall condition of the cab. Note any broken or cracked glass, dented sheet metal or structural rust.

1. Cab: Make sure the glass is intact and the ROPS hasnt been damaged. The seat should be in good working condition and should rotate easily. Loader and bucket commands should respond quickly to controls. Heating and air conditioning should be operating correctly. Check service and parking brake.

2. Engine: Engine oil should be free of dirt and grit. Inspect the engine for blow-by. The oil filter and air filters should be clean. Check the radiator for antifreeze. Determine which parts (if any) of the engine have been rebuilt.

3. Tires and Axles: Inspect the tread and look for gashes on the sidewalls. Make sure kingpins are greased and fit tightly. There should also be oil in the axles. All lugs should be present and fit tightly.

4. Hydraulic Cylinders: If scratches are present, oil will eventually begin to leak out. A loss of pressure will hinder the machines performance.

5. Loader Bucket: Inspect the cutting edge. There should be no more than 50-percent wear.

6. Frame: Look for welds and other signs of damage. If the frame is bent, chances are the machine was involved in a roll-over accident. Cracks indicate the machine has been overstressed.

7. Stabilizers: Make sure the stabilizer cylinders are in working order and that there are no hydraulic leaks the stabilizer cylinders are damage-prone. The stabilizer pads should be intact. Check cylinder rods for scratches.

8. Pins and Bushings: Examine all hinge parts, particularly the kingpin. Rust buildup around these areas indicates the machine has been sitting idle for an extended period of time.

9. Backhoe Boom, Arm and Bucket: Check for non-manufacturer welds, which would indicate the arm or boom has been repaired. A broken arm or boom will likely break again. Bucket teeth should be in good shape and all bolts in place.

10. Hydraulic Hoses: Look for signs of pinching and excessive wear. If the hoses are dry and brittle, they need to be replaced.

1. ROPS: Check ROPS for dents or welds.

2. Transmission: Transmissions can be fully checked only by being operated. Does the dozer steer and brake properly? On clutch brake systems, feel if the machine brakes and steers left and right equally and thoroughly. With hydrostatic systems, in addition to the above, check for noise and vibration.

3. Engine: The engine compartment should be checked for signs of leaks, both below the engine, and around head gaskets and valve cover gaskets.

4. Covers: Examine the dozer for an excessive number of structural dents, and note any major welds. Both could be signs of abuse or severe-use applications.

5. Hydraulic Cylinders: Check all hydraulic cylinders for leaks, and note any dents or damaged areas on the rams.

6. Blade: On blades, make sure the unit is solid, without structural damage. Note any wear on the teeth or edges. Make sure theres enough shim left protecting the structure. If blade face appears rippled, it may need to be reskinned.

7. Push Beams: Push beams are subject to a great deal of stress, and should be examined for any structural weaknesses (cracks) or repairs (welds). Make sure that any welds are done properly.

8. Roller Frame: Check roller frame for cracks and welds.

9. Undercarriage: Since the undercarriage is such a critical cost component of a dozer, consider paying for a certified inspection.