With a diesel-heated screed, determine the condition of the heater boxes and screed frames. “The frames of the screed see a lot of fatigue because of the heating and cooling cycles,” Sunkenberg says. “You are basically taking a diesel burner and scorching the metal. There are only so many times you can do that before the steel starts to rot, crack, or lose its integrity.” With an older machine the heater boxes often rot. “The frame that you bolt the heater boxes up to will be cracked, fatigued, or rotted away,” Sunkenberg says.
According to Sharp, “Physical damage to strike-offs, extenders, or end gates will be visually seen in the mat. Damage to electrical harnesses and heating elements can be easily checked with a meter. Tripped circuit breakers can indicate issues with the integrity of the system. If equipped with a diesel heating system, things to check include glow plugs, fans, and switches.”
Indicators of abuse
The hopper wing can provide insight into the care of the paver. “If it is clean and straight, the company took pride in the unit and ran it the right way,” says Bolick.“If it is bent and the paint has come off, the machine was not taken care of properly.” Hoppers take a lot of abuse due to truck exchanges, hopper inserts, and heavy mixes.
“The front hopper flashing on most pavers is probably the most exposed component on the paver — varying truck dump height and hopper overloading takes a toll on this material,” Sharp says. “Push rollers and truck hitches also take abuse due to truck contact and visibility issues.
“Hopper inserts are designed to contain large, heavy quantities of mix, leading to increased stress on welds and hinges,” he adds. “A good indicator of the structural integrity of the hopper is to look for rub marks on the bottom, outer side of the wings. If the wall thickness has been worn too thin, contact between the hopper and undercarriage can cause rub marks when the wings are folded down. Check wall thickness to ensure that the hopper can still support the weight of inserts and mix.”
“A flared-out hopper may cause a little bit more spillage than a hopper that has its original shape, but it should not be a huge performance issue,” Sunkenberg states. “But a hopper will tell you the duty cycle a machine has gone through. If you pave a lot of cul-de-sacs and parking lots where the truck needs to turn out away from the paver, that is how you might bend up the hopper.”
“Undercarriage components such as belts, planetary gears, drive wheels, and bogies get exposed to abuse from uneven terrain, heavy loads, and other hidden dangers,” Sharp says.
“For continuous rubber track machines, the condition of the track must be considered,” Hutchins says. “The condition of these parts can drastically change the value of a used machine.”
“Belts must be carefully inspected to ensure that punctures and tears have not damaged the internal banding,” Sharp says. “Many times, a visual inspection of the edge of the track belt can determine its overall shape. If cracks or exposed banding layers are present, failure may not be too far off.
“On wheeled machines the front bogie wheels are exposed to heavy loads and should be inspected for bent shafts. Oil samples of the planetary gears can expose contamination and are a good indicator of the condition of internal components.”
Next, check the hydraulic system. Hydraulic components — such as feeder motors, vibration motors, etc. — may require replacement, depending on the age of the machine. “Typically, pumps and major powertrain components live as long as the machine when properly maintained,” Hutchins notes.
Also make sure the hydraulic system is free of leaks and contamination. “All hydraulic levels should be at specifications. Leaking seals could drip oil onto the paved surface, which could cause mat failures,” Sharp says. “Oil samples and pressure readings can be useful for indicating whether pumps and motors are within the standard operating range. Cracked hoses should be replaced to avoid failure at inopportune times.”
“Always ask for maintenance records,” Hutchins adds. “A history of fluid samples is fantastic if the previous owner was consistently maintaining the machine and taking fluid samples. A stand-alone sample at the time of the sale tells you nothing. Take pressure readings from the pumps, motors, etc. and check for any leaks or strange sounds.”