How to: Inspect a Used Wheel Loader

Linkage pins and the center pivot are key inspection points.

By Marcia Gruver Doyle

Dennis Nalon, used equipment manager with Walter Payton Power Equipment, Lebanon, Indiana, likes to start his used loader inspections by getting the general lay of the land. “I go around the machine and note any basic problems with tires, sheet metal, windows, and linkages,” he says. “I look for things that jump out, then I’ll go into specific details.”

There are a number of items that would raise immediate red flags in this initial inspection: cuts in a tire sidewall or tread, cracks in the wheel area, obvious cylinder and hose leaks, missing grease zerks, excessive wear on the bucket, and cracks, welds, and plates on the frame. These would all be signs, Nalon says, the loader has been through some hard times.

Always check the hour meter and, if possible, have an inspection partner along who’s knowledgeable about loaders. Our inspection machine is a 2007 Doosan DL300 with 650 hours on it. That may not seem like many hours, but this rental machine in Walter Payton’s fleet has spent the majority of its life in demolition applications — hence the foam-filled tires and underneath plating.

Tires and wheels

The significant cut on our machine’s left front tire is not the concern it would be if the machine had regular pneumatic tires. With regular tires, however, there are several things to watch out for in addition to cuts, all of which could be safety hazards. A ripple on the sidewall could indicate there’s been a tearing of the interior liner. Check tire pressures and verify there are no issues with the rim of the wheel. Also look for missing wheel lug nuts or bolts.

When you check the tread on all tires, note the raised wear width in the center of the tire, Nalon says. When that is worn down, you’ll want to pay closer attention to getting it replaced. Nalon says he would advise replacing the tire after it gets another 1/8-inch past the point the wear width has gotten even with the surrounding tread.

“Look on the back side of wheels and tires to make sure there’s no oil or debris that’s caught up in there, especially in a machine used in demolition,” Nalon says.

And don’t forget to inspect all four tires. One tire’s condition — whether good or bad — doesn’t necessarily mean the other three tires are in the same shape, or even the same size.

Engine compartment

Do the usual fluid checks, looking at the condition and level of the engine oil, antifreeze, and hydraulic oil. Check the belts for wear and possible replacement. As always, be on the lookout for leaks, both around the engine and the radiator. “You never want to start the engine if you see an oil or antifreeze leak or a belt that’s starting to come apart,” Nalon says. “First, replace the belt and determine where the leaks are coming from, then you don’t have to worry about a belt flying and hitting someone, or a leak spraying oil and causing a fire.”

Look at the air cleaner indicator to see if the air cleaner needs to be changed. Make sure the air inlet to the turbocharger is intact and there are no tears in the tube. If tears are present, replace it immediately, since dust bypassing the air filter could get into the engine and cause an engine failure.

Examine the filters: do they look like they’ve been changed? Pull out the air filters and check them.

When you run the engine, listen for noises and observe the smoke coming out of the exhaust. Look at the dashboard indicators to see if there are any diagnostic issues with the engine.

Transmission

The transmission is located at the center of the wheel loader, underneath the cab. Check the transmission oil dipstick and look at the level indicator to make sure there’s sufficient oil. Look for leaks, and take care of them before you start the machine.

Hydraulics

Check all cylinders and hoses for leaks and try to determine each leak’s origin. Other areas to look for leaks include the hydraulic pump, the area where the drive shafts go into the rear ends, and axle seals.

Hoses are susceptible to leaks, especially at the crimp fittings and at the O-ring face seal fittings. Perform a pressure check on the system to make sure you’re getting the pressure you need.