Heavy Duty/Off Road
Technical Session

Getting information out to the individuals that need to know is
what the technical sessions at the MACS convention is all about,
and the Hvy Dty/Off Road session was no exception.  New techniques,
advanced testing procedures, and overviews of existing procedures
were all part of the topics covered in this year. 

        Morning classes started off with
Mike Maxwell and Tom Wilkins from
Noregon Systems introducing the
newest in diagnostic capabilities for
the heavy duty technician.  JPRO is
a software based system that allows
for interaction with all major heavy
duty engine platforms, ABS, transmissions,
and HVAC systems.  With just one simple
click on the easy to read screen a
technician can go from engine back to
transmission without ever having to
change scanners.  Over a dozen OEM
and independent manufacturers’ scanner information can be integrated to the JPRO for quick and easy access.
   As Mike and Tim will tell you, “You can’t fix what you can’t see. The JPRO allows you to link all of the systems under one application.  Every Truck, Every Time.”  With over 2,800 OEM codes in use today and the fact that some of these codes can only be seen on certain platforms the ability of the JPRO to interact with all of these different software applications makes the technicians diagnostic time much quicker and easier than ever before.   JPRO, definitely a tool for every commercial fleet and Hvy Dty/Off road service center.

        To finish off the morning session Instructor Tony Yerman with TLY Consulting schooled us in RV air conditioning repair issues. As Tony told the crowd right from the start, “It’s not the air conditioning that is necessarily going to be your problem but the way it is configured in the vehicle.”
Tony went on to explain the difficulties in reaching a solution with the variety of manufacturers involved, the types of A/C systems, and the numerous locations. Not to forget how an owner may mistakenly block vents, slack on general maintenance, or perhaps be the recipient of some construction material left in the ducting that nobody knew about.  As well as animal intrusion, insects, and accident related damage that can also add up to poor air flow. But air flow is only one part of the diagnostic issues that you need to be concerned with.
        Unlike a passenger car, where there is only one power source a motorhome has several options for the needed energy to operate the A/C.  These all can be potential sources of voltage and amperage problems. 
   “It’s not uncommon to have a wire color change several times from the front to the back of the unit depending on how many sub-assemblies and/or vendors a certain system had to go through,” Tony went on to say.
        A typical engine mounted system may have the compressor and a section of the pressure hoses supplied by the chassis vendor while the evaporator core, condenser, or drier units may be supplied by a different one.  Even the dash controls might come from a different outside source than everything else.  As Tony reminded us all at the end of the session, “Think out of the box in order to start your diagnostic testing”

       The afternoon classes had a lot to offer as well.  Al Leupold a long time presenter at MACS (now with Bergstrom) was up first and brought us up to date on A/C preventive maintenance issues.
“HVAC system repair ranks 3rd just behind tires and brakes respectively,” Al told the group.
Finding the proper tools, information and avoiding poor product information were just some of the highlights Al’s detailed lecture covered.  Al went on to tell us, “The ultimate goal is to satisfy the customer.  Look at the cost of NOT training your technicians rather than the cost to train them.”   I totally agree, the lack of training only means a lack of satisfactory results for the customer.
        Al also focused on the importance of maintenance, and that more than 75% of most A/C breakdowns could have been avoided if proper maintenance would have been done. These maintenance issues not only involve the customer’s car but also your equipment. He pointed out that the lack of maintenance on recovery machines, gauges, vacuum pumps, and scales could end up with even poorer results.

        Dan Spurgeon was up at the podium next to give us some input on problems with HVAC systems on Caterpillar equipment.  Dan had some interesting insight on compressor mounting, hose routing, and leak detection on Caterpillars.  One of his key points he wanted to stress to the audience was, “No one (leak detection) method is best for all situations. Have a variety of methods ready to use.” 
Dan also gave a great description on how size and length of pressure hoses promoted oil flow through the air conditioning system.  His presentation also included some great photos of vehicles and their related problems taken in the field.  Definitely an interesting class for the afternoon.

        Leo Chernavsky came up to the stage next with some very interesting facts and figures on moisture in an A/C system.  “1 drop of water equals .05 grams.  4 drops of water will produce a concentration of 200 ppm in 1 Kg. of 134a,” Leo informed the group.
Leo went on to give a detailed procedure on using Nitrogen to evacuate the moisture from the system as well as how to properly handle components before final fit up. 
        “Water can only be removed as a vapor, any liquid present must boil out,” Leo told the group.
All in all, Leo did a great job of explaining the procedures and what would happen if you didn’t remove moisture from the A/C system.  Very informative and well presented.  Nice job Leo!

        Gary Hansen, Vice President and Chief Technical Officer with Red Dot was up next and brought his skills with compressor lubricants to the stage.  “All synthetic oils are not created equal. There are many grades and additive packages available,” Gary said.
        Knowing the right type of oil for the right type of application was a big part of Gary’s lecture.  He also explained what and how viscosity played a part in the variety of compressor oils, and why metal cans were far better than plastic to purchase your oils in.  “Keeping a good selection of oils in smaller metal cans will greatly reduce any moisture issues with your inventory,” he said.  A good point to know, especially in a shop that deals with several different types of A/C systems.

        Trans Air finished up the afternoon class with Kermit Walden at the helm. Talk about saving the best for last!  That’s not to say everything else up to this point wasn’t top notch… far from it… they were all superb.  Kermit took the class into the realm of leak detection in a whole different way. He covered routing issues, fittings, and how to isolate a leak to one line (with some rather cleaver homemade fittings to seal off each end of the hose) by applying 200 to 250 psi of pressurized nitrogen and performing a “bubble” test to the fittings and lines.
        He also covered the use of a MICRON gauge and how the last inch of vacuum is around 2300 microns while a good pull down value is 500 microns.  A very well rounded day of A/C information from the Heavy Duty/Off Road technical training team. 

       A tip of the hat to one and all… great classes and great instructors.  If you didn’t get a chance to attend, check with MACS for more information and do your best to attend the next convention.  You won’t be disappointed.

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