This is the first of two informational pieces from Bendix to aid vehicle owners and service providers in preparing for Brake Safety Week 2015, which will be held next week. For more on Bendix’s safety tips, please click here.
Inside the cab, Bendix says it’s important to know the vehicle systems’ blinking light fault codes and how to address them. Antilock braking systems (ABS) warning lights convey key information on problems with components such as wheel speed sensors.
If the vehicle is equipped with traction control and stability control systems, Bendix says the traction control/stability control lamp will indicate any issues. Blinking light fault codes for both ABS and traction control/stability control systems can be accessed using the dashboard diagnostic switch or a remote diagnostic unit. Using the fault code information in the service data sheet, drivers and technicians can pinpoint and address sensor issues.
Day-to-day, maintaining a clean air system is a priority. Bendix says components such as air seals, brake modulating valves, and brake chamber diaphragms are susceptible to premature damage if an air system is contaminated by moisture – and, in particular, oil. Deterioration of seals can cause air system leaks, which are targeted during Operation Airbrake inspections. Bendix recommends monthly checks for moisture in the air brake system, along with installation and regular replacement of oil-coalescing air dryer cartridges.
Conduct effective pre-trip visual inspections, with an eye out for problems such as loose hoses and leaks. At the wheel-ends, Bendix says to visually check that the air chambers are not damaged and hanging loose or with broken push rods. Check foundation drum brakes for lining cracks, linings that may have been oil-saturated due to leaking wheel seals, and broken cam brackets. As long as there are no dust shields, linings can be checked without removing the wheel. And if the vehicle is equipped with air disc brakes, check the rotors for cracks or grooving and make sure the caliper is sliding freely, the company says.
Bendix also advises more in-depth preparation includes regular, detailed inspection of the brake friction, checking the linings for thickness, cracks, and wear; and measuring the brake stroke. In addition, check the cam bushings and replace if out of specification, as well as lubricate the cam tube until grease purges.
For fleets and drivers operating vehicles equipped with automatic slack adjusters (ASAs), Bendix says it’s important to remember not to manually adjust the ASA if the brake is beyond the stroke limit. Drivers can incur fines if 25 percent of a truck’s wheel-ends are beyond the maximum allowable brake stroke (out of adjustment). Simple maintenance, such as greasing the slack, can keep the ASA working smoothly and in proper adjustment. Several factors – including improper lubrication of the camshaft, cam tube, and clevis pins; or excessive wear of the cam head, bushings, and rollers – can cause a brake stroke to exceed the maximum allowable value, but none of these will be fixed by manual readjustment of an automatic slack adjuster, Bendix says.
“Last year’s Brake Safety Week saw about one in ten vehicles placed out of service for brake adjustment,” says Frank Gilboy, slack adjuster product manager with Bendix Spicer . “Because properly installed and maintained ASAs should never need adjusting after the initial setup, we emphasize the need to learn and address the possible causes of ASA-equipped brakes going out of adjustment, which has a direct impact on brake performance and vehicle safety.”
For Part II from Bendix on managing inspection day, please CLICK HERE.