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Best Practices for Trailer Maintenance

By March 1, 2014 No Comments

My job takes me into trailer repair shops of every type, size and variety. Some of the maintenance programs that I have seen deserve to be buried and forgotten; but there are some worth sharing about so we can all learn and improve. After all, in the age of the FMCSA’s Compliance, Safety and Accountability (CSA) program (, everyone needs all the help they can get just to maintain, let alone try to improve, their CSA score. I also informally interview CMV inspectors every chance I get so I have a pretty good idea what they see and what they are looking for during roadside inspections. Read on to find out some of the best practices to help you improve performance, save money and pass roadside inspections.

The key to fewer roadside inspections

Check your lights! The overwhelming majority of CMV inspections occur because an officer sees a light out and pulls a CMV over–such a simple thing, but one that starts a process that can lead to expensive roadside repairs and/or fines. A conservative estimate is that the time spent on the side of the road costs $500 per hour. To avoid this as much as possible, your trailer maintenance program needs an advanced diagnostic tester that lets one technician use a remote control to activate each electrical circuit as he walks around the trailer once. The best testers monitor the electrical circuits for faults and sound alarms and display the cause of the faults.

The number one reason trailers are placed OOS is due to brakes and/or brake adjustment. This is followed closely by tires being unfit for service, and next after that are air leaks. The CMV inspector is going to get under the trailer to perform a thorough visual inspection of the brake system components, and measure the brake strokes with a 90 to 100-psi brake application per TMC recommended practices. Including this test as part of your company’s inspection and maintenance program on a regular basis will help you be in the best possible position to pass roadside inspections.

There is help available to make this job fast and accurate. Advanced testers let you apply and release the brakes via remote control while you are under the trailer, watching the brake components move and measuring/adjusting brake stroke length. The best testers are regulated to provide the same air pressure for a brake application as the inspector will use. Remember to do a leak-down test on both air lines at the same time. Since you are already there, conduct a quick visual inspection of the tires and listen for air leaks. With the right tester, you can check all the hot items–lights, brakes, tires and air leaks with one technician and less than 10 minutes of shop time. That is a good investment, trading 10 minutes of shop time for all of the expense and hassle of roadside inspections and/or repairs. When the wheels are turning, everybody is happy!

Another best practice is to pay for performance. Reward drivers and shop technicians for passing roadside inspections. Do this and your drivers will perform pre- and post-trip inspections without fail, and will insist the items be fixed before they head down the road. Take a chance! I am willing to bet that your reward payout will be a smaller investment than the money saved on road repairs and/or fines. Everybody wins—you are making money and as an added bonus, morale goes up too.

Want to save $$$?

The key to fast inspections and accurate fault isolation is technology. Advanced diagnostic testers help every shop tech do the job faster and help you save considerable money on parts. Consider ABS troubleshooting; many shops consider this a “black art” and so only one to two technicians or the shop supervisor take on the challenge of working on ABS faults–but with what kind of results? ABS ECU manufacturers report that 75 percent of all units returned to them under warranty are in fact good. That is a terrible percentage and makes my point that advanced diagnostic testers are needed to help analyze electrical circuits and ABS faults. The best testers use TMC Recommended Practices to make sure that the primary and secondary power to the ABS ECU are within tolerance before the ECU can be communicated with. If the ECU does not have proper power, it will only give erroneous results, so fixing the power issues is the first step.

It is my opinion that most technicians just change the ECU when presented with this scenario; when in fact, just cleaning up the corrosion and wiring issues to fix the ECU power issues would fix the problem. This is a crucial concern when you consider that the typical ECU costs between $500 and $900 and it takes on average three to four hours of shop time to change one out. Refraining from needless replacement of good ECUs could add up to some serious money-savings very quickly. Want some icing on the cake? Not spending four hours replacing a good part gives your technician the opportunity to work on other, needed jobs and the savings or increased revenue just keep adding up.

Improve performance of lower-level technicians and employee morale

Provide technicians with a rugged, all-in-one, advanced diagnostic tester, with troubleshooting diagnostic software built-in to the tester, and the performance level of your shop will go way up. The best testers are extremely intuitive and so easy-to-use that even entry-level technicians can test and diagnose air leaks, brake issues, electrical circuits and PLC ABS faults. Testers should test to TMC Recommended Practice standards to ensure that the testing is done correctly and that you are getting the expected results.

Every time I see a shop invest in an advanced diagnostic tester, it is amazing to watch how the technician morale goes way up. After a few short weeks, you will not be able to separate the technicians from their beloved tester. Testers do require an investment, but one that has a definite payback in terms of labor savings, parts savings and fewer roadside repairs. And as an added bonus, your CSA score probably improved, as well.

In conclusion

You have probably surmised that an advanced diagnostic tester is the key to improving your trailer maintenance performance level while saving money and passing more roadside inspections. I gave you the big hitters; if you want to do even better, just inspect those things regularly and thoroughly using advanced testers (probably not as difficult as you were thinking at the beginning of this article). Yet, some of you will say “We never needed tools like that before. We will get along just fine without them.” CSA will eventually put the “nails in the coffin” of shops run with that mentality. If you travel as much as I do, you will notice that there are fewer repair shops and fewer fleets than there used to be. These were the technology laggards that failed to adapt, improve and invest in the tools required for today’s trailers. I sincerely hope that you will instead embrace change and invest in your future. After all, CSA is here to stay.

Dennis Zerbst, Sales