Trailer maintenance often takes a backseat to servicing the truck, but it’s vital to ensure that all components are working properly.
A quality on-time preventive maintenance inspection for trailers is the best way to increase uptime, decrease running cost, ensure safety and prevent violations, said Matt Krasney, vice president of fleet management for Penske Truck Leasing.
While trailers obviously are less complex than powered vehicles, there still are key areas that require regular checks.
Inspect, don’t neglect
The most neglected maintenance areas on trailers are the kingpin, the brakes and lubrication, said Cindy Crawford, group director of maintenance and engineering for Ryder Fleet Management Solutions.
A list of weekly and monthly checks should be developed to complement a driver’s pre- and post-trip inspections, said Mark Sabol, platform product manager for East Manufacturing.
“It’s about visual inspection,” said Steve Zaborowski, senior vice president for Xtra Lease. “If you see something’s wrong, you investigate it. If you see something that just doesn’t look right, you shouldn’t just let it ride. You should stop, take a look at it, and make sure the system is working in accordance with how it was planned to be used.”
Weekly checks should include looking for structural dam- age and verifying that all lights function, are in place and are not obscured.
“Lighting issues are easy to identify, which makes them a target for inspections and violations,” Krasney said. “Check for damaged lenses and clean, strong connections in the wiring. Loose connections, water intrusion and corrosion are all common culprits when it comes to lighting failures and can be prevented with proper maintenance.”
Sabol recommends checking the electrical system for chafed wires, missing clips and positive grounding.
Next, he suggests lubricating the fifth wheel, checking for corrosion between the plate and the main rail and looking for loose or missing bolts, cracks and unusual or excessive wear before checking the kingpin for tightness.
Ryder performs more than 200,000 PM inspections per year and emphasizes inspection of the kingpin and the upper plate. “This carries the entire load of the trailer and can often get overlooked in a preventive maintenance inspection,” Crawford said.
The kingpin’s minimum diameter can be checked with a go/no-go gauge, she said. “These are the only components holding the connection between the tractor and the trailer while allowing them to pivot when turning.”
Crawford said contaminants should be cleaned from the upper plate with a scraper to view the plate for damage. Lubrication and inspection are critical for long life of these components, she said.
Moving further down the trailer, check the landing gear mounting plates and bracing for cracks, visually inspect all air springs and airlines for chafing, and check the brake valves for leaks and proper operation, Sabol said.
“Check for and remove any foreign material from within the dust shields, and drain the condensation from the air reservoirs,” he said.
Crawford recommended keeping your top Compliance Safety Accountability violations in mind during PM checks. “Brakes are usually one of the top areas for most companies,” she said. “Opportunities can include the anti-lock brake system. Automatic slack adjuster brake stroke is another area to focus on.”
Keeping them rolling
A tire failure is the most likely cause of a disabled trailer. Craig Porter, operations manager for McCoy NationaLease, pegs rubber as the top trailer maintenance cost.
Sabol suggests checking air pressures regularly and inflating according to the tire manufacturer’s recommendations. Next, verify that the wheel lug nuts are tight.
“Pay particular attention to tire pressure, tire tread depth and the overall condition of the tire, damage, tread separation,” Krasney said. “If the trailer has a tire inflation system, be sure that the system is activated and operating correctly, including the warning light, and that all hoses and tubes are correctly installed and not leaking, and that the pressure is correctly set using a high-quality calibrated gauge.”
Brett Wilkie, field service engineer for advanced design and material for Wabash National, said many fleets that do not use tire inflation systems have switched from plastic valve caps and are using inflate-through metal caps, a good alternative that also offers labor savings.
Next, check the oil level in the wheel hubs to ensure proper wheel bearing lubrication, inspect the seals and hubcaps for leaks, and grease all Zerk fittings, Sabol said. Wheel bearings should be checked for excessive wheel-end play.
“Lubrication should be a key area of focus, and brake components are also very susceptible to poor lubrication practices,” Crawford said.
In addition to the weekly checklist, Sabol recommends a monthly check of all welds for cracks and an inspection of the suspension system bushings for excessive wear and freedom of movement.
“Check that the bolts are tight,” he said. “If the bolts are below the required torque of 225 pound-feet, re-torque. If bolts are below 225 pound-feet more than once, replace the bolts.”
Check these out, too
Krasney said there are many other systems and components to inspect and maintain beyond tires, brakes and lights.
“Keep the exterior of the trailer clean, especially the undercarriage during winter months,” he said. “Don’t forget the rear-impact guard. It needs to be damage-free, securely attached and correctly labeled.”
Crawford said that while most of a trailer’s base components – such as the brakes, tires, suspension, frame, sliding tandems, kingpin and bumpers – are the same, specialized equipment will need additional inspection criteria.
“Flatbed trailers may have ratchet straps or a forklift mounting that need to be inspected,” she said. “The basic inspection items are the same for most trailers, but we find that adding transport refrigeration, liftgates, forklifts and pintle hooks increases the need to change the PM inspection items.”
“One practice doesn’t fit all,” Porter added.