As spring is just around the corner, it’s come time once again to assess just what sort of toll winter has had on your brakes. Chemical de-icers and salts have been known to cause serious corrosion issues, particularly when they aren’t washed off regularly. In the Northwest, where record snowfalls fell this winter, combined with record cold temperatures at times, may have made truck washing difficult to impossible.
More recently, the Northeast has been socked with epic snowstorms, which kept many drivers off the roads for days. Now, those drivers will be scrambling to get back on schedule, which may not leave much time to get their trucks washed.
That’s all the more reason damage assessments on your rigs and trailers will be very important, particularly if the Commercial Vehicle Safety Alliance’s unannounced brake check day comes before its 30th annual Roadcheck – June 6-8, like it did last year. Then there’s CVSA Brake Safety Week. Last year, inspections held during brake safety week revealed brake–related out-of-service violations in 13.2 percent of vehicles – a slight increase compared to the previous year’s result. If those results are any indication, truck drivers and fleets would do well to look closely at potential damage from this year’s punishing winter conditions.
If you don’t already have a copy of the CVSA brochure on the North American Standard Inspection Program, get it and store it on your smartphone or laptop for easy reference. Or better yet, take it to a copy shop and have it printed and laminated – then you can access it anytime.
If you’re unsure where to start, look first for those conditions that would get your truck declared out-of-service by a roadside inspector. By fixing those issues first, you may improve your chances of keeping your truck on the road. When 20 percent or more of the service brakes on your truck or truck-trailer combination don’t work properly, you probably should expect to be sidelined. Plus, any inoperative brake or missing brake on either wheel of the front steering axle, or mismatched air chamber sizes, defective lining conditions or mismatched brake adjuster lengths on drum air brakes can lead to out-of-service violations. Similar defects found on air disc brakes and hydraulic brakes on the front steering axle can also get your truck 86’d from the road. Refer to FMCSR Section 396.3(a)(1) for more information.
Here are some other suggestions from brake manufacturers and service providers that we’ve seen published in several leading trade magazines like Fleet Maintenance and Heavy Duty Trucking:
Air compressor, air dryer, air dryer purge valve and air tanks
- One of the most critical parts to the braking system, and to several others that use compressed air on your truck, is the air dryer. When the compressor draws in air, it also brings in moisture. If that moisture gets past the air dryer, it can condense inside the air tanks and eventually make it into the braking system. If you didn’t replace the air dryer cartridge in the fall, which is when Bendix recommends annual replacement, replace it immediately with an OE cartridge, preferably an oil-coalescing cartridge. Oil aerosols passed by the compressor can be particularly harmful to air systems;
- If you didn’t replace the air dryer’s purge valve in the fall or early winter, do that as well, particularly if your truck was running frequently in the Northeast and Northwest during the coldest months. Going forward, consider this another annual replacement to be done in the fall in preparation for winter;
- Manually drain the air tanks periodically, based on your truck’s air usage. Once a month for high-use applications or every three months for the typical line haul application;
- Check the air system for leaks. Bendix recommends a 90 to 100 psi brake application, followed by a walk-around vehicle inspection listening for audible leaks. When conducting a visual inspection, check for loose hoses;
- If any part of your air system froze this winter, and you used methanol or alcohol to thaw or to de-ice the system, carefully check for leaks around the brake valves if the O-rings were exposed to the anti-freeze compound. Leaks can be audible, or can be detected using soap spray. If the valve is leaking, either replace the o-ring or the entire valve;
- For future reference, avoid using de-icing compounds when the air system freezes if at all possible. If you must use them, determine the precise location of the freeze-up and try to limit application only to that area.
Brakes, brake components and wheel ends
- Check the friction on brake pads for cracks or missing pieces and ensure adequate thickness;
- Examine drums and rotors for signs of dragging brakes or overheating linings;
- If you have a truck equipped with brakes that meet the federal reduced stopping distance regulations, when you need to reline the brakes, be sure to ask your parts supplier for the evidence of compliance;
- When you or your mechanic service your truck or truck-and-trailer combination, be sure to look closely for excessive wear of the cam head, bushings, or rollers; proper installation of the slack adjuster; and proper operation of the slack adjuster per the manufacturer’s procedures such as Bendix Air Drum Brakes Service Manual BW-7258;
- Remember never adjust automatic slack adjusters to correct for out-of-adjustment conditions. Repeated out-of-adjustment conditions on automatic adjusters may be a sign of another issue. Technicians should look for the root cause;
- At the wheel-ends check to see that the air chambers, pushrods and slack adjusters aren’t damaged or hanging loose;
- If your truck is equipped with air disc brakes, look at the guide pin boots and tappet boots and make sure they are intact, with no cracks or tears that could allow moisture to invade;
- While it’s not necessary to get under your truck during every pre- or post-trip inspection, Bendix recommends doing this at least once or twice a week to check air disc brake rotors for cracks and the wear of the lining on drum brakes without dust shields.
Other suggestions
- Become familiar with your vehicle systems’ blinking light fault codes and know how to address them;
- Check out the American Trucking Association’s Technology and Maintenance Council Recommended Practice (RP) 627A. It offers inspection guidelines that align directly with those of the CVSA. And visit the Bendix On-Line Brake School at brake-school.com. It offers access to company’s knowledge database, product education and technical resources.