The National Association of Trailer Manufacturers (NATM)‘s fourth annual Trailer Safety Week is taking place June 6–12, 2021. The purpose of this nationwide event is to raise awareness about the importance of trailer safety, educating people about proper maintenance practices and equipment usage, and help drive overall road safety.
Safety is always important to us and one of our core company values, which is why we are excited to help raise trailer safety awareness. Below are some of our Maintenance department’s top tips to prevent dangerous breakdowns over the road and, as our friends at the NATM would say, “Making Roadways Safer One Trailer at a Time.”
Tip #1: Brake Drum Heat-Checking
Heat-checking is the appearance of numerous short, fine, hairline cracks on the braking surface of the drum. Heat-checking is a normal condition found on brake drums and is caused by constant heating and cooling. Heat-checks will frequently wear away and form as a result of the normal brake process. However, heat-checks can progress over time into cracks in the braking surface depending on factors such as lining wear rate, brake system balance, or how hard the brakes are used. Normal heat-checking does not impair braking performance; however, it is advisable to make sure that deep cracks have not developed. Replace the brake drum if heat checks, either one or more, extend completely across the brake surface. Heat checks crack when they are 0.06 inches wide and/or 0.12 inches deep or greater.
Tip #2: Corrosion–Keep Your Warranty Intact
Most trailer light manufacturers have somewhere between ten years to lifetime replacements on LED trailer lights and markers. Trailer harness manufacturers usually carry between a five- and ten-year warranty on trailer wiring harnesses– unless there is corrosion present. Corrosion at any pigtail, harness connection or seven-way box will void any factory warranty. Corrosion is caused by a combination of things– road grime, calcium chloride, moisture and air are just some of the leading contributors of corrosion in our trailer wiring systems. Did you know that there’s a minimum of 36 marker light connections on every trailer, not including ABS connections? The best way to keep your warranty intact is to follow these simple corrosion preventions tips:
Regular Cleaning: Cleaning the electrical connections systemically with a small wire brush reduces corrosion.
Dielectric Grease: It is a non-conductive, silicone-based grease that is used to keep moisture away from electrical components. It should be used on each electrical connection. Most trailer light manufacturers have dielectric grease in the terminal ends of the pigtails and marker light bases. So, if you are installing a new pigtail and base that already have dielectric grease in it, you do not have to add dielectric grease to the connection.
Hydraulic Lock: When it comes to more dielectric grease–more is not better. Don’t create a hydraulic lock. A hydraulic lock is created when too much grease increases the surface’s tension on both mating surfaces. The excess fluid pressure actually pushes the mating surfaces away from each other. This can actually cause a marker light not to work.
Tip #3: Tire DOT Identification–What do the numbers mean?
New Tires: The DOT number appears on the sidewall of all tires intended for sales in the U.S., and designates the location of the manufacturer, the week and year of production, and the specific tire. DOT codes prior to the year 2000 were a ten-digit code: (Ex. – AD70449248) digits one and two indicated plant of manufacturer code. Digits three and four were the tire size code; five, six, and seven were optional tire type codes; and eight, nine, and ten were the production serial week code. (The example would have been produced in Mayfield (DOT plant code AD), the size code would be “70”, the optional design code would be “449”, and the serial week would be “118”). In the year 2000, the serial number went to an 11-digit number allowing for a four-digit serial week code to identify the new decade.
Retread Tires: Under the new Regulation, the first two symbols must identify the week of the year by using “01” for the first full calendar week in each year, “02” for the second full calendar week, and so on. The final week of each year may include nor more than 6 days of the following year. The last two symbols must identify the year. For example, 0101 means the first full calendar week of 2001, or the week of January 7th through 13th, 2001. According to the new specifications, the minimum size of the date code may be reduced from 6mm (1/4”) to 4mm (5/32”). This allows the figures to fit the same space as the old three-digit code. Although 4mm is the minimum size, there is no limit to how large the figures can be.
If you’re interested in learning more about this topic, be sure to check out our blog that details how you can extend tire life.
Tip #4: Brake Lining Inspection
Technicians are asked almost daily to inspect trailer brake linings for serviceability. For the purpose of this article, defects have been placed into two categories: out-of-service and in-service. Structural defects listed as “in-service” will provide adequate brake performance but should be repaired as soon as possible. Defects listed as “out-of-service” constitute a fully defective brake and are conditions which: (a) if present on a steering axle, it would place the vehicle out-of-service: (b) if found on 20 percent or more of the brakes, it would place the vehicle out-of-service.
Out-of-Service: According to CVSA, a defective brake is defined as one or more of the following conditions:
- Lining cracks or voids over 1/16” in width observable at the lining edge.
- Cracks that exceed 1- 1/2” in length.
- Missing portions of a lining segment suck that a fastener (i.e., rivet or bolt) is exposed when viewed from the lining edge.
- Cracks extending across the lining face through the lining edges.
- Loose lining segments. (Approximately 1/16” movement in any direction).
- Complete lining segment missing.
In-Service: While the following defects are not considered “out-of-service” conditions, operators should remain alert to them and arrange for appropriate repairs as soon as possible.
- Any vertical or horizontal cracks in the lining edge that exhibit no loss of material. The width of the crack should not exceed 1/16”. Length of the crack should not exceed 1-1/2”.
- Brake linings with 1/2” or more of missing corner segment with no fastener (i.e., rivet or bolt) exposed.
- Brake lining cracks on lining face that extends from fastener hole to fastener hole.
- Pitting and material erosion on the lining face.
- Scoring or contamination on the lining face caused by road debris.
Tip #5: ICC Bumper Requirements
- The ICC Bumper must extend horizontally to within four inches of the side of the trailer and not beyond
- The distance between the bottom of the bumper and the ground must not exceed 22 inches at any point.
- The rear surface of the bumper must be within 12 inches of the rear service of the trailer, and the height of the bumper must be at least 3.94 inches.
Pre-Trip Inspection Hints!
In a time-critical industry like transportation, a thorough pre-trip inspection can save both you and your company many hours of downtime that could have been spent on the road making deliveries. The key to a good inspection is to take your time while working systematically around each section of the trailer performing each check fully. A thorough pre-trip inspection ensures the safety of not only the driver but also everyone on the road while saving time and money.
- Make sure the PM/Annual date is current and the paperwork in the registration matches the date recorded on the PM/Annual sticker. An overdue or missing date on the appropriate sticker is a DOT Out-of-Service condition.
- Always inspect the seven-way receptacle for loose or broken pins. Broke or loose pins will not allow the trailer lighting system to operate properly. This may lead you to operate in the dark.
- Make sure the glad hands are secured properly and the seals in the gland hands are free of cuts or tears. A bad glad-hand seal can cause air leaks which can produce braking problems later down the road.
- Make sure the registration holder is secured to the trailer as designed and seals properly. It’s hard to read wet, or even worse, missing paperwork.
- When inspecting lights, ensure that no bare wires or corrosion is present. Even if the light is working upon your initial inspection, a bare or corroded wire can be a sign of potential problems down the road.
- Inspect the dolly leg, sandshoe, crank handle, and bracing for loose or missing bolts. Make sure there are no jagged edges on the crank handle. In addition, ensure that it’s secured properly to keep from injuring the driver while in use.
- Make sure all hoses, tender springs, and electrical wires are not chaffed and that they are secured properly. Chaffed air hoses can lead to air leaks and are an out-of-service condition. Hose separators are an inexpensive way of keeping airlines from rubbing the axle and/or each other.
- Inspect the hubcap for the proper oil level which can be seen through the sight class. Do not drive if oil cannot be visibly seen on the sight class! Hubcaps void of oil leads to brake failures, fire, or catastrophic failures over the road.
Trailers are one of the few items in the transportation industry that are operated by many drivers and, at times, many companies. For this reason, performing a proper pre-trip is vital and can significantly reduce the risk of something unsafe happening during transport. To lower the chance of failure, and/or costly accidents, take the time to perform a thorough pre-trip inspection!
For more information on Trailer Safety Week 2021 or to order trailer safety publications, check out the official page: trailersafetyweek.com.