{"id":3408,"date":"2019-09-03T13:51:10","date_gmt":"2019-09-03T11:51:10","guid":{"rendered":"http:\/\/en.advancedfleetmanagementconsulting.com\/?p=3408"},"modified":"2019-09-03T13:51:10","modified_gmt":"2019-09-03T11:51:10","slug":"avoiding-unplanned-downtime-with-proper-air-system-and-brake-maintenance","status":"publish","type":"post","link":"https:\/\/advancedfleetmanagementconsulting.com\/eng\/2019\/09\/03\/avoiding-unplanned-downtime-with-proper-air-system-and-brake-maintenance\/","title":{"rendered":"Avoiding Unplanned Downtime With Proper Air System and Brake Maintenance"},"content":{"rendered":"

\"Those<\/p>\n

Those unwanted \u201cgotchas\u201d that lead to\u00a0unplanned downtime\u00a0could have been prevented by adhering to prescribed maintenance guidelines and best practices. Photo courtesy Bendix<\/p>\n

Avoiding Unplanned Downtime With Proper Air System and Brake Maintenance<\/h2>\n

Parts fail: It happens occasionally in even the most maintenance-conscious fleets and drivers. Often, though, the service and support teams at Bendix encounter reported failures or problems \u2013 those unwanted \u201cgotchas\u201d that lead to unplanned downtime \u2013 that perhaps could have been prevented by adhering to prescribed maintenance guidelines and best practices.<\/p>\n

Here are some helpful tips on how fleets and drivers can prevent key air system and brake components \u2013 air dryers, compressors, automatic slack adjusters, and air disc brakes \u2013 from failing due to improper maintenance practices to keep vehicles on the road and in good operating condition.<\/p>\n

Air Dryers<\/h3>\n

Moisture in a vehicle\u2019s compressed air system isn\u2019t good: It can lead to corrosion and reduce the effectiveness of lubricants. Mix it with oil aerosols, and water can contaminate valves and deteriorate seals, impacting everything from brake performance to automated manual transmissions. A properly functioning air dryer is absolutely crucial \u2013 and dryers are a regular point of discussion on the so-called warranty pile.<\/p>\n

\u201cWhen someone can\u2019t get water out of their air system\u2019s service tanks, the assumption tends to be that there\u2019s something wrong with the dryer,\u201d said Richard Nagel, Bendix director of marketing and customer solutions, charging. \u201cA lot of the time, though, we find that other factors have come into play, and that the dryer itself isn\u2019t the culprit. There are physics to an air dryer that you can\u2019t get around, and if the science rules aren\u2019t followed, you\u2019ll have a dryer that doesn\u2019t remove enough moisture.\u201d<\/p>\n

For instance, Nagel noted, dryer location and routing of the discharge air line from the compressor to the air dryer matter greatly but aren\u2019t always properly considered. A dryer mounted under the hood, for example, may be in an environment that doesn\u2019t allow for the required temperature differential between its hot side and cold side. Additionally, the discharge line may not be sufficiently cooled.<\/p>\n

Compressors<\/h3>\n

Water in the service tanks might also be a result of a mismatch between the output of the air compressor and the capacity of the air dryer, especially in systems equipped with larger compressors to meet high air demand.<\/p>\n

If there\u2019s too much air demand, the dryer\u2019s charge-and-purge cycle may not provide enough desiccant regeneration since the compressor is running constantly and the dryer is not purging enough moisture to keep the desiccant from saturating. In cases like this, a vehicle might require an extended purge dryer or a continuous flow dryer, or even two dryers in tandem.<\/p>\n

If the system is experiencing difficulty building air pressure, Nagel also suggests looking small before thinking big: \u201cJust look for leaks,\u201d he said. \u201cSome of our dryers have multi-circuit connections with multiple fittings and hoses connected; sometimes you\u2019ll find small cracks in air hoses; and sometimes you\u2019ll find discharge lines clogged with carbon. None of these issues requires replacing a compressor or dryer.\u201d<\/p>\n

Automatic Slack Adjusters<\/h3>\n

Out at the wheel-ends, automatic slack adjusters (ASA) represent another not-uncommon component found in the warranty pile.<\/p>\n

\u201cWe see plenty of slack adjusters come back for a warrantied replacement, but when we take them apart, it\u2019s immediately apparent that they haven\u2019t been recently or properly greased,\u201d said Keith McComsey, Bendix Spicer Foundation Brake director of marketing and customer solutions, wheel-end. \u201cWhen you neglect this simple bit of preventive maintenance, the grease inside a slack becomes very clay-like as the lubricity breaks down and contaminants build up, which prevents it from functioning as it should.\u201d<\/p>\n

Greasing an ASA serves two vital purposes: Forcing the new lubricant in purges the old grease, along with any water or contaminants that have found their way in; and it protects the adjuster\u2019s internal gear sets, clutches, and other components from wear. Both are necessary to maintain correct brake stroke and provide optimal stopping performance, and all it takes is injecting new grease through the grease fitting. You will see old grease exiting the purge hole in the rubber boot; continue until you start to see new grease exiting. That is the signal that you have successfully replaced the old grease with new grease. It should take less than a minute per adjuster and can easily be handled during preventive maintenance inspections.<\/p>\n

Air Disc Brakes<\/h3>\n

The right upkeep also matters greatly to the life and performance of air disc brakes (ADB), where something as simple as selecting the wrong aftermarket replacement pad kit can have severe consequences. Choosing an overly aggressive friction can lead to stress cracks or heat cracks in the rotor, for starters \u2013 but there are also important details in kit accessories that are often overlooked.<\/p>\n

\u201cBendix benchmark testing of other aftermarket pad kits in the market demonstrated a 40% reduction in pad retainer spring force (on average). A kit that comes with a weaker pad retainer spring can damage the retainer bar and\/or the carrier because the pad will have more movement during brake applications and vibration,\u201d McComsey explained. \u201cIn the long term, this can lead to a damaged carrier, and potentially even break the retainer bar, which could lead to other extensive damage beyond the brake.\u201d<\/p>\n

He continued, \u201cWhen it comes to shear adaptors (a pad kit component used to back brakes off\/set running clearance), other aftermarket pad kit benchmark testing has shown non-Bendix\u00ae shear adaptors shearing at 1.5-times higher torque value (on average) than Bendix\u2019s.\u00a0 Adaptors that shear at higher torques run the risk of damaging your adjuster (the caliper internal mechanism); once that happens, you\u2019re forced to replace the entire caliper. Using the wrong pad kit will void your caliper warranty since other aftermarket kit pads do not perform the same, nor do they use OEM hardware like Bendix does to protect the rest of the system.\u201d<\/p>\n

McComsey also stressed the importance of regular preventive maintenance and inspection practices, including checking and measuring ADB friction for thickness, checking for caliper slide-ability, and making sure caliper boots and chamber seals are intact to prevent contaminants from getting inside.<\/p>\n

While Bendix prides itself on its technical support, stressing over a part that may be headed for the warranty pile doesn\u2019t make anyone\u2019s day brighter. The proper maintenance practices \u2013 those detailed in the service data sheets and other support tools from Bendix \u2013 can help keep that from happening.<\/p>\n

This article originally appeared as part of the\u00a0Bendix Tech Tips series<\/a>, found in the Bendix multimedia center at\u00a0knowledge-dock.com<\/a>.\u00a0It was\u00a0edited according to the standards of HDT to provide useful information to our readers.<\/em><\/p>\n

by Bendix<\/p>\n

Source:https:\/\/www.worktruckonline.com<\/a><\/p>\n

FLEET MANAGEMENT AUDIT<\/h3>\n

Fleet management is the use of a set of vehicles in order to provide services to a third-party, or to perform a task for our organization, in the most efficient and productive manner with a determined level of service and cost.<\/p>\n

Fleet management activities are shown in the following graph 1:<\/p>\n

\"fleet<\/p>\n

Graph 1: fleet management activities<\/p>\n

The proposal audit analyses and assesses all fleet management activities shown in the graph 1, and its main goals are:<\/p>\n