Truck Parts and Service | Heavy Duty Trucking, Aftermarket, Service Info
Issue link: http://read.dmtmag.com/i/290319
13 Tech Updates W W W . T R U C K P A R T S A N D S E R V I C E . C O M A p r i l 2 0 1 4 | T R U C K P A R T S & S E R V I C E C ompressed air has a variety of uses in today's commercial vehicles. According to Bendix, it is impera- tive to proactively maintain air systems to ensure each component operates at peak performance. This includes the air dryer system and associated valves and reservoirs, the company says. Inspecting an air dryer system should begin with opening the drain valves on the reservoirs to check for moisture in the system, Bendix says. If moisture is present, technicians should verify that no external air has been applied to the system, and check the air dryer's service data sheet to confi rm that the air dryer is mounted in the correct location with the correct discharge line length. If external air was applied, Bendix says to then drain all reservoirs and purge tanks, restart the vehicle, and allow system pressure to build to the governor cutout pressure. Techs should then verify the proper system pressure has been reached, and then operate the vehicle normally. Bendix says techs also should recheck for water in the reservoirs after one week. If an issue with the air dryer mount- ing or plumbing is encountered, Bendix warns to have it corrected, and ensure the discharge line from the compres- sor to the air dryer slopes continuously downward to the air dryer inlet, with no water traps. Bendix also notes to take into account any signifi cant temperature changes within the previous 24 hours. Ambi- ent temperature shifts of greater than 30˚F can cause a temporary accumula- tion of moisture, the company says. If a signifi cant temperature change occurs, continue to operate the vehicle under normal conditions. The small amount of water that may have condensed due to the temperature shift will be reabsorbed by the dry air once the vehicle is in operation, Bendix says, then check the air system again after one week. Whether moisture is present in the system or not, Bendix says to check all the air lines for damage such as chafi ng, and examine the air dryer mounting bolts for tightness and torque as specifi ed in the manufacturer's service data sheet. Within the air dryer system, Bendix says there are three key components to monitor: the air dryer cartridge, the purge valve, and the delivery check valve. MAINTAINING AN AIR DRYER SYSTEM P roperly maintaining a vehicle under CSA guidelines begins with proper inspection, accord- ing to Phillips Industries. Fleets and service facilities should educate and train their drivers and customers on how to properly conduct pre-trip and post-trip inspection re- ports, which includes properly record- ing vehicle defects in the DVIRs (Driver Vehicle Inspection Reports). When possible, Phillips recommends inspections go beyond the minimum re- quirements by checking the vehicle every time it's parked. One of the top reasons a vehicle is pulled over for inspection is because an offi cer spots something wrong, for example, a defective light. By inspecting a vehicle regularly, driver can identify easy-to-spot defects and avoid getting pulled over. Phillips says motor carriers also should ensure their drivers know any vehicle malfunction or maintenance problem must be addressed proactively to prevent crashes. A driver needs to notify maintenance staff and service providers about any defects found dur- ing an inspection as soon as possible, whether through the daily inspection report, or some other means. If minor issues are found that can be repaired while on the road after leaving the yard, Phillips says it is suggested that the driver keep the following items on hand: TIPS TO ENSURE CSA COMPLIANCE Pocket continuity testers for plugs and sockets Plug and socket brush Extra 7-way socket and 7-way plug Hose holder and hose separators Extra tender spring Handful of dielectric grease packets Two (2) universal gladhands and extra gladhand seals Cable ties Extra lights Wire stripper and crimping tool Conspicuity tape Emergency tire infl ator Emergency hose repair kits Basic tool kit Flashlight (with an extra set of batteries)