General Motors’ Allison Transmission is introducing its new Allison DOC (Diagnostic Optimized Connection) For PC Version 4.0, a full-feature diagnostic software application supporting control systems for Allison transmissions.
Mack Trucks recently received a $1.2 million contract through Southwest Research Institute to develop diesel hybrid electric technology that will ultimately be used in military and commercial vehicles. The majority of the work is to be performed at Mack Powertrain in Hagerstown, Md.
Webb Wheel Products is recalling all Platinum Series Brake Drums with cast date codes 017-01 to 273-02 (Julian style date) for premature friction-surface cracking.
Sirius Satellite Radio and Penske Truck Leasing announced a multi-year agreement to offer Sirius satellite radios in specific lease, commercial and consumer rental vehicles.
According to the CK Marketing and Communication’s Q1 2004 Fleet Sentiment questionnaire, 68 percent of responding fleets plan to purchase power units in the next six months; 60 percent also plan to buy trailer equipment during the same period.
ChevronTexaco Global Lubricants announced that motorsports legend Mario Andretti will conduct an autograph and photo session at the CTGL booth at the Technology & Maintenance Council’s Annual Meeting on Tuesday, March 16.
Ample oil usually is a good thing, but not when it comes to air dryers – vital components that help ensure your brakes get clean, dry air. An air dryer’s internal workings would last forever except that oil from the compressor eventually works its way into the dryer and keeps the desiccant beads from grabbing water the way they should. So the desiccant bed and oil separator (if so equipped) have a limited life – normally about one to three years.
Because the desiccant bed and oil separator have much shorter lives than the rest of the air dryer, the components are assembled into the dryer together as a replaceable cartridge. The single most important aspect of dryer maintenance is replacing that cartridge at the right time. As with almost everything in trucking, the duty cycle of the truck greatly affects cartridge life. Brake air system maintenance also plays a big role because leaks mean the compressor handles more air, and that means more water for the dryer to take out.
More routine air dryer maintenance consists of draining the wet tank and primary and secondary storage tanks periodically. This, says Larry Donaldson of the Bendix Tech Team, serves as a check of dryer function and should be done at least every 25,000 miles, 400 hours or three months, whichever comes first. Jon Canale, senior project engineer, Meritor WABCO, says it’s smart to do this as often as once a week.
If the dryer is the right one for the application, and the air system is in reasonable condition, a lot of moisture in the tank – normally mixed with some oil – means it’s time to replace the cartridge. “It’s normal to see a tan colored goo in the air stream that some describe as ‘mayonnaise,’ Canale notes. “Some is normal, but you should not have much if the dryer is working properly. You’ll just see a little mix in the initial blast of air. In ideal applications, there won’t be any.”
Canale also advises that fleet managers don’t need to empty air tanks when they drain them. “Just pull the cord and hold it open for a few seconds, so you can see what comes out.” Completely draining the tanks interferes with dryer performance, putting some water downstream until things stabilize.
If oil is accumulating around the purge valve and just below where the exhaust port is, you should at least examine the cartridge, Canale says. Heavy evidence of oil there can be a sign of an incorrect installation of the dryer on the vehicle, such as a line between the compressor and dryer that’s too short. It definitely means the cartridge isn’t working the way it should if there is also oil in the air tanks and bottom of the dryer. That means the cartridge is saturated with oil, and it’s passing right through.
