Nationwide, there are an estimated 20,000 school bus technicians turning wrenches, changing oil filters, and testing brake responses.

An increasing number of those are ASE certified (5,417 at latest count) but where can technicians go to get training in the first place? The answer, for many, are maintenance training sessions offered by various engine and parts manufacturers, designed to familiarize mechanics with a particular school bus engine or part and how problems can be diagnosed and quickly repaired to get the school bus back on the road with minimal delays.

So, just what is out there for school bus technicians?

Four maintenance training sessions are spotlighted and while there are no doubt many others of value to technicians, those offered by Allison Transmission, Cummins Engine Co., Deere Power Systems, and Navistar International warrant particular attention. For more information on any of the maintenance training sessions discussed here, contact your local distributor.

North America's largest producer of school bus transmissions covers the full spectrum of transmission installation, service, and overhauls in classes ranging in length from two to five days.

The material for those classes is established by company headquarters in Indianapolis although Allison distributor trainers nationwide are free to customize any of the programs should their clients express an interest in a program not already in place, said Brenda Ross, Allison's manager of technical publications and training.

In all, 14 classes are offered with more coming in the year 2000. Of the existing classes, many are of interest to school bus technicians, including the World Transmission service class. It spans five days, covering the system's operation, construction, service requirements, installation guidelines, and troubleshooting procedures. Classroom topics include torque converter operation, power flows, clutches, retarder operation, vehicle interface, electronic and hydraulic control systems, and preventative maintenance. Hands-on instruction includes volt-ohm meter use, connector repair, and Pro-Link diagnostic tool basics.

The AT500 and MT600 series overhaul classes cover similar topics applicable to the transmission series. The classes last four and five days, respectively. Allison's service manual and parts catalog is used to help disassemble, qualify parts for reuse, and reassemble the transmission.

Allison Transmission classes are offered across the United States and Canada, as well as in Singapore, Australia, Brazil and The Netherlands.

Cost to attend sessions range from $220-$440 per person, depending on the course. Prices may vary slightly between locations.

The maintenance training sessions offered by the Evansville, Ind.-based engine builder are operated nationwide by Cummins distributors. The decision on what to include in the curriculum is left up to individual distributors.

Cummins Cal Pacific, Inc., in Irvine, Cal., offers classes ranging in length from one to five days focusing on a variety of maintenance topics. Available for technicians are courses dedicated to electronics theory and troubleshooting, engine operation and maintenance, and thorough examination of the company's school bus and truck engines, including the ISB and ISC products.

Technicians attending a training session are offered hands-on training and state-of-the-art operational engine training modules. Instructors are Cummins employees, each of whom are certified yearly to ensure they provide the latest information and techniques available.

Cummins trainer Ron Callaway teaches most of the classes in Irvine while the remainder are lead by experts from companies such as Valvoline.

The 1999 courses are offered based on individual engine families or in some cases, multiple engine families within a given market. For example, technicians seeking ISB engine qualifications need to take the three-day Basic Electronics Theory and Troubleshooting (BETT) session, the one-day Windows/Insite course, and the four-day ISB Qualification session. The Windows/Insite course teaches technicians to navigate through diagnostics and programming software used to diagnose various Cummins products. The ISB qualification course includes component identification, systems flow, wiring diagrams, and a host of hands-on activities involving fuel pumps, injectors, and heating circuits.

Callaway said courses also examine the differences between gas and diesel engines, various oils, and lubricants.

Upon completion of the ISB and/or ISC engine courses, technicians receive the appropriate qualifications

Cummins Cal Pacific, Inc. offers maintenance training courses through Aug. 30 in Irvine, Calif. Costs range from $125 to $625 per person.

Technical training is offered for John Deere OEM engines, specifically the Power Tech 6068/6081 HFN (Compressed Natural Gas) advanced engine systems.

The two-day course, limited to 12 participants, provides technicians with an in-depth knowledge of the CNG engine fuel systems and hands-on diagnostic procedures. Among the topics discussed: combustion theory, air flow, fuel flow, air/fuel management, sensor circuit theory, and diagnostics. The diagnostics training includes practice at solving engine problems with diagnostic fault codes, engine systems without fault codes, and control system testing. The course is offered through Oct. 20 in locations such as Palm Desert, Calif. and Dubuque, Iowa.

Deere Power Systems Training Coordinator Dee Dee Lutgren said the company has paid closer attention to the needs expressed by its dealers and distributors in recent years to help shape the type of technical training sessions offered. Courses are taught by both Deere employees and contracted instructors who have significant histories in the area of their discussion.

At the conclusion of each session, attendees fill out evaluation forms which Lutgen said are compiled and used to offer better sessions the following year.

Also offered in 1999 for school bus technicians is the Power Tech 4045/6068/6081 advanced engine systems, adjustments, and overhaul course: a 4 ½-day meeting, again limited to 12 participants.

The course exposes technicians to the construction and subsystems of the three engines with 70 percent of the course time devoted to hands-on instruction. Classroom discussions take up the remaining 30 percent. The final course is slated to take place Sept. 13-17 at a yet-to-be-determined location in the western United States. Cost is $80 per student, per day.

Arguably the most comprehensive technical workshops at least in term of their national scope are International's School Bus Chassis Maintenance training sessions.

The Chicago-based bus builder is in the midst of a 55-city (up from 30 in 1998) training session program in 1999 which wraps up Dec. 6-8 in Orlando, Fla. and New Orleans. The three-day sessions center on the orientation, maintenance, and diagnostics of a wide range of international school bus chassis components, including the DT466E and T444E diesel engines, hydraulic brake systems, air brake systems, power steering systems, electronics, and recommended maintenance practices.

"We try to stick to the technology (technicians) are working with," said John Richter, manager of service personnel development at International who oversees the technician training sessions.

Instructors are not International employees, many are maintenance experts from Delta College in Saginaw, Mich., who are selected by International and put through the company's training program before being placed in the classroom.

Richter said the training sessions offered in 2000 will pay closer attention to technological changes with a greater emphasis on fleet software diagnostics and the company's Diamond Logic material. Like Deere's technical sessions, much of the subject matter for upcoming sessions is based on technician comments received at the conclusion of each session the preceding year.

Cost for the three-day sessions is $550 per person. It includes 24 hours of training and training material. While no sessions are planned for additional U.S. cities in the near future, Richter said expansion into Canada is a possibility.