top of page
Writer's pictureRALPH COPE
May 26, 20215 min read

SIX Things to Look for when Buying a Used Excavator


A used excavator can either be a money pit or a gold mine. It can either do a great job of extracting cash out of your pocket or be an exceptional source of income. In order to ensure the latter scenario, here are SIX pointers on what you should look out for when buying a used machine to ensure that you extract the best possible return on your investment. 1) Inspect the Machine in the Cold Hard Light of Day

Excavators don’t need to look pretty in order to become a reliable source of income. However, the aesthetics of the machine will tell you how it has been maintained by the previous owner. You do not want to inspect the machine at night. You want to use daylight to help you run a thorough inspection and get a general idea of how it has been treated. You would rather buy the machine from a small company or a single-use owner. This means that it has not been used by a hundred different minimum wage operators that have thrashed the living daylights out of it. Your first prize is buying the machine of an owner-operator.


2) Pay Careful Attention to the Pivot Points

Excavators tend to walk less than bulldozers, which means the life span of their undercarriages is longer. The principle strain on the excavator, therefore, tends to be concentrated in the boom, the arm, the bucket, and the cylinders. You want to look at the pins and bushings of these pivot points. The strain on these points will be determined by the work the machine has done. If the excavator has been used to move rubble and rocks there will be greater wear in the pins and bushings compared to a machine that has been moving topsoil all of its life. You want to check the grease fittings on these pivot points. You will be able to tell whether these points have been regularly lubricated or whether they have been ignored. It is a good idea to take a grease gun with you to the inspection for three reasons. By greasing the points you will see a) how much grease it takes to get the grease to come out b) the colour of the grease that comes out and c) to see if the grease fitting can even take the grease (the old grease may be so heavily caked inside that it does not accept the new grease). Another pivot point you want to check is the ring gear. An easy inspection is to swing/slew the machine and listen for grinding below the cab where the ring gear is located. Not only is it expensive to replace the ring gear, but the logistics of lifting the upper section of the excavator of the undercarriage can also be expensive because you may need to hire another excavator to do so. 3) Check for Cylinder Damage It is unlikely that you will find a second-hand excavator that is 100% oil-tight. Do not get stressed out if you find one or two. A leaking cylinder means that the seals need to be replaced. That is a relatively simple and cheap exercise. You do, however, want to check for damage on the chrome rod of the cylinder. You want this rod to be perfectly smooth. If there are any dings or damages on the rod, they will cause the seals to wear out quicker. You will need to replace those seals with greater frequency. Although the expense is not great, the machine downtime is going to cost you time and money.


4) Send Plenty of Time Inspecting the Undercarriage

This is the bottom substructure of the machine and the point of impact with the ground. You firstly want to check the sprockets. The more rounded or smooth the teeth of the sprockets the better. If they are razor-sharp like a knife, it means that they have been exposed to considerable wear and will need to be replaced. Having said this, it is not costly to replace a sprocket. Secondly, you have the top and bottom rollers. Here you want them to be as rounded as possible. Also, listen to hear if they make a loud squeaky noise when the tracks are moving. There should be no play in the rollers – if there is, the bearings are shot. Like the sprocket, rollers are not expensive to replace. Thirdly, you want to closely inspect the chains (also referred to as links). Again they should be as rounded as possible. If they have been worn into the shape of a C, it means that the tracks are older and have a limited lifespan in front of them. These flat spots in the links are caused by sharpening in the sprockets. Fourthly you want to check the grousers (also referred to as shoes). You want them to be tight on the tracks with a limited amount of play. Finally, you need to look at the track adjuster. Again, you must listen for noise when the machine is moving. Also, if the adjuster is extended far out forward, it means that the chains are stretched and may soon need to be replaced which is going to cost you money.


5) Check the Filters and Oil before Starting Her Up

Check the oil, fuel, hydraulic, and air filters. Pull the air filter out to make sure that it is not packed with dirt. Then check the oil levels and look for leaks. When you fire the excavator up, check to see how quickly it takes. If it fires up the first time without much fuss, it is an indication that your engine is nice and tight. After firing up the machine, the first thing you want to look at is the exhaust to ensure that there is not too much smoke coming out. Secondly, on the engine, you want to make sure there are no leaks. You want to open up the oil cap and look for blow-by. You will know there is blow-by if there is oil around the cap, when oil is flying out the opening, or when you lift out the dipstick and oil is bubbling out.


6) Drain the Final Drives You will need to drain the oil on the final drives and check for filings. You also need to check to see if the oil is new. New oil can sometimes be problematic and an indication that the seller is trying to hide a defect in the final drive. The bottom line is that you do not want to oil to be too clean or too dirty – both these situations should sound warning bells. Once the oil has been drained, remove the cover and check the gears for wear. Again, you want to ensure that the teeth on the gears are not too sharp.




Comments

bottom of page