8 Best Practices for Trailer Maintenance

When you think of maintaining your fleet or your individual rig, the tractor, not the trailer, always seems to get all the attention. Although the trailers of today are designed and manufactured to last longer than those of a few years ago, they still need proper maintenance to stay safe and on the road. We've compiled a few trailer maintenance tips to help ensure your trailer, or trailers, are always in top operating condition.

1. Check The Air Pressure

We cannot express enough the importance of making sure tires are operating at proper inflation levels. If you've installed and are using tire pressure monitoring/inflation systems, make sure you inspect these systems for leaks.

As you know, tires are a major expense, so they deserve proper attention. Proper tire air pressure has always been the key to tire longevity. Often, drivers are too busy to check tires regularly, so inflation pressure monitoring systems are recommended. With that said, these monitoring systems need their own attention...you, or a technician, needs to regularly check the supply hose connection to the tire and occasionally look for leaks.

We recommend three safety checks:

  • Verify the system pressure is set accurately
  • Check the auxiliary battery switch (ABS) and/or the auxiliary power fuse
  • Also, check the system shut-off valve position

In addition, check the regulator pressure at least once a quarter, as well as check the power fuse monthly, as the driver-warning lamp will not illuminate without power. Also, the system shut-off valve should be checked every time there is a visual inspection of the trailer. If your tires are properly inflated and you’re still seeing tire wear, the problem is probably not with the tires Unusual tire wear is an indication that you may have something wrong with the undercarriage, suspension, shock absorbers or axle alignment.

2. Lube Your Rig Correctly

While not the most comfortable thing to do, it’s necessary to crawl under the trailer to inspect undercarriage components. The correct lube in the right amount, is important for proper trailer operation. Grease has three characteristics, the thickening system, grade and performance rating are all important in selecting the right lube.

Also, don’t mix the two greases, as performance will drop. About 90% of greases are lithium complex based, but some are calcium based. The grade of the grease speaks to its viscosity and most grease used on trailers is NLGI, which has the consistency of peanut butter. The performance of the grease can be harder to determine, as not all lube manufacturers put this information on the label. Consult with the lube manufacturer to ensure you’re getting a grease with the proper performance characteristics. Lastly, make sure you add enough new grease to purge the old grease. It’s not that the old lube wears out, but the dirt and debris that cling to the grease make it ineffective. Adding new lube actually gets rid of the dirt.

3. Inspect Your Suspension

Visually inspect suspension components, keeping an eye out for signs of irregular wear, tears or heat cracks on the air springs. Also make sure air springs have sufficient and equal pressure. Also, note that every air suspension has a defined ride height position... If the ride height is not correct, you will not receive benefits of an air-ride suspension. If too high, you may not clear low clearance areas, and If there is too little air, instead of riding on the air bag, the trailer will ride on the suspension’s bumpers, which damages other suspension components.

4. Check... Your ... Brakes.

You, or a technician, should check drum conditions while performing brake or wheel end service. Measure the drums to make sure there is enough material to last until the next maintenance inspection. If it’s borderline, replace it. On wheel ends with spring brakes applied, check the angle formed by the air chamber push rod and the slack adjuster. The angle should be close to, if not 90 degrees. If it isn’t, the brake is probably out of adjustment and needs to be repaired.

5. Keep Your Rear End Clean

Your lighting and electrical systems are susceptible to corrosion. Inspect connections and replace lamps as needed. Road de-icing chemicals don’t just attack electrical connections, they also attack metal parts. Regularly wash equipment after exposure to these chemicals... always wash the underside where chemicals can remain undetected and for long periods of time. A clean trailer also allows you to more easily spot trailer problems... we recommend trailers be washed every 45 days, and brought into a shop every 45 to 60 for a more thorough inspection.

6. Keep The Lights On

A burned out trailer light is asking for trouble... you're just asking to be pulled over for a roadside inspection. Moisture and corrosion is the leading enemy of an electrical system, and road salt attacks all electrical connections. When the correct steps aren't taken to prevent corrosion, it can spread throughout a trailer, significantly shortening its life. Regularly inspect lamps, wires and harness systems and replace the grease when needed at connection points.

7. Maintain Inside &Out

While you may do a great job looking at the outside the trailer, you may forget to inspect the inside. Regularly look for deep scrapes or holes in the roof, as well as broken aluminum cross members. Holes in the roof can cause leaks which could damage your loads, as well as letting in potentially damaging moisture or "critters" into the trailer.

8. Security Check

Your trailer maintenance must always include a close inspection of tie-down straps, ratchets, chains, and winches. Look for holes, tears, snags, cuts, or loose stitching in the straps and also near the securing hardware. Note...Washing tie-downs is not recommended, as this act has an adverse affect on the nylon tie-down straps, and actually will cause the dirt to work its way into the nylon fibers, reducing strap integrity and work load limits. This is one case where dirty straps are better than washing. Lastly, make sure your winches are regularly lubricated, and your ratchets oiled to keep them in good working condition.