Broken equipment in the field can impact the productivity of an entire operation. Downtime can put a project behind schedule and lead to wasted man-hours and increased costs. Fleet managers rely on field service trucks to quickly solve issues in the field to reduce downtime and safely and efficiently get the equipment back in the dirt.
Because these trucks are so heavily relied on to increase productivity, maintaining field service trucks and their components is just as important as performing regular maintenance on other machines in a fleet to keep operations running smoothly.
“A well-run equipment fleet needs a well-maintained mechanics truck in order to keep equipment in the dirt and earning money,” says Terry Cook, product manager of commercial products at Iowa Mold Tooling (IMT). “Making preventive maintenance just as much a priority for your service trucks as you do for your equipment is worth the investment.”
A properly maintained service truck allows a fleet to be more productive when all of its components are working properly. It also ensures the safety of the technicians and mechanics who operate the truck and its components.
Mileage drives maintenance on trucks and other vehicles, but technicians use a service truck’s components while the vehicle is stationary. Mileage is generally not an ideal way to schedule maintenance on the service truck’s components.
“Our components are based on hours of usage,” says Tim Davison, product manager, bodies and cranes, for Stellar Industries. “Basing [maintenance] on hours of use is a more accurate method in relation to construction equipment, so it’s not in the best interest to schedule [maintenance] with the miles driven on the chassis.”
Stellar and other manufacturers often provide recommended maintenance schedules for field service trucks, which include logs to help technicians track inspections and repairs. Built-in hour meters help technicians track the time spent using each component.
These logging techniques can help technicians coordinate component and chassis maintenance.
“By including the hour meter readings for cranes and compressors in fleet maintenance tracking systems and comparing to recommended maintenance intervals, the equipment maintenance can be planned along with the chassis maintenance,” says Cook. “Coordination of mileage- and hours-based schedules is a matter of comparing both sets of data and looking for good opportunities to perform equipment maintenance with chassis maintenance, at or before recommended service intervals.”
The following are the main components of field service trucks and the recommended preventive maintenance steps for each.
Daily inspections of a service truck’s crane should include checking all safety devices and hook safety latches for proper operation. Technicians should also check for hydraulic system abnormalities, proper oil level and any leaks, cracks or other abnormalities on the crane itself.
According to Cook, maintenance should be performed on a service crane every three to four months or after 300 hours of operation—whichever comes first.
During this quarterly maintenance, wear pads should be examined for general condition and replaced if necessary. Proper torque of all accessible and base mounting bolts should be checked and adjusted, and structural components of the crane should be examined closely for any necessary repairs.
Yearly, or every 1,200 hours, the crane’s control and safety valves should be inspected and calibrated for the correct pressure and relief valve settings. Additionally, hydraulic fluid should be changed and the rotation drive system should be inspected for proper backlash clearance, as well as abnormal wear, deformation and cracks.
“We recommend that technicians inspect their service body at least weekly, if not daily, when performing a walk-around inspection before starting their day,” Cook says.
Technicians should look for hydraulic leaks, broken transportation or safety lights, and any abnormalities in the structure of the truck. The inspection should extend to the underside of the truck body, checking for low-hanging or dragging hydraulic plumbing or electrical wiring.
This inspection could save on further maintenance down the line.
“If a hydraulic leak goes unnoticed, it could potentially cause a catastrophic failure and dump all the system oil,
so if a leak is spotted, the operator should react quickly,” Cook says.
In addition to performing inspections, technicians should ensure that the truck is kept clean.
“Not keeping the service body clean can lead to unsafe working conditions and prevent technicians from noticing potential maintenance problems,” says Cook. “The dirtier the truck, the less likely you are to see a crack.”
Cook says that no matter the model of air compressor on a service truck, the airend oil level should be checked daily. Before starting the compressor, technicians must ensure that the tanks have been drained of condensation. Once the unit is started, it is important to check that it is building pressure and for any leaks in the air lines or fitting.
Oil should be changed and cooling vanes cleaned every 250 hours of operation or every three months. Every six months or 500 hours, the drive coupling must be inspected for wear, and the air cleaner should be changed.
Wire rope and hook
As vital components of the crane, the wire rope and hook must follow their own daily inspection and maintenance schedules.
Corrosion on the rope should be carefully monitored, and the rope should be replaced if corrosion leads to breakage in the wires. Areas of the rope that are hidden or located over sheaves experience the most wear and should be regularly lubricated to prevent corrosion.
According to Cook, if a rope has three broken wires in one strand or a total of six broken wires, the rope should be replaced. Flat spots on the outer wires; distortion such as kinking, crushing or birdcaging; and a decrease in diameter, which indicates a core failure, are all additional causes for wire rope replacement.
“If you don’t inspect your wire rope as suggested in the inspection log book and it has been damaged, it can eventually snap or break and cause a catastrophic situation,” Davison says.
Hooks should be monitored daily and if found to be damaged, should be removed and replaced immediately. Hooks with deformities, cracks, nicks or gouges, or that are bent or twisted should be removed from service. They should also be replaced if they exhibit wear that exceeds 10 percent of the original dimension.