Time and miles: Both seem to roll by more quickly than we realize. Consider six months, 1,800 operating hours, or 50,000 miles — for many working trucks and truck drivers, those aren’t long intervals: But they’re key markers for a piece of basic wheel-end preventive maintenance that’s too often overlooked.
This installment of the Bendix Tech Tips series reviews greasing automatic slack adjusters (ASAs), the importance of keeping up with their regular lubrication schedule and other related wheel-end practices to enhance uptime and safety.
Dual-purpose PM
“There are two vital purposes to greasing an automatic slack adjuster,” says Keith McComsey, director of marketing and customer solutions, wheel-end. “First, it protects the adjuster’s internal gear sets, clutches and other components from premature wear. Second, the action of forcing new lubricant into the ASA purges the old grease, along with any contaminants or water that have found their way in. Both support vehicle safety by maintaining the correct brake stroke and providing optimal stopping performance.”
It’s not uncommon for Bendix technicians to encounter automatic slack adjusters that haven’t been greased regularly. Neglecting this simple bit of maintenance leads to the grease inside an ASA becoming clay-like as it accumulates contaminants and loses its ability to lubricate the slack. In addition to impeding performance, by impacting the brake stroke, this condition can put a vehicle out of compliance with stroke regulations. Fortunately, it’s easily avoidable, Bendix says.
The American Trucking Associations’ (ATA) Technology & Maintenance Council’s (TMC) recommended practice (RP) for greasing ASAs lines up with those interval numbers mentioned earlier: Every six months, 1,800 operating hours or 50,000 miles, whichever comes first. And lubrication is a simple process that generally takes less than one minute per adjuster.
Easy as 1-2-3
