Fabian Rojas
Corona
Summary
Experienced Heavy Duty Technician with approximately 15 years in the heavy-duty transit industry. Specializing in inspections, diagnostics, troubleshooting and repairs on heavy duty CNG transit public transportation buses, CNG transit school buses, diesel tour buses, diesel school buses, propane powered school buses, gasoline powered Ford and Chevy school buses. Proficient in troubleshooting and repairing complex systems including electrical, electrical charging, engine, HVAC, steering, suspension, hydraulic, gas/ fire suppression, air brakes, wheelchair ramps, cooling system, air system, camera systems, child check mate/ theft alarm systems and transmissions. Demonstrated ability to manage technician assignments and create detailed work orders using softwares such as Ellipse, Hexagon and infor while maintaining accurate fleet and operations hold lists on Excel spreadsheet and DCS software computer program. Skilled in performing on-road diagnostics and repairs safely.
Overview
14
14
years of professional experience
1
1
Certification
Work History
Heavy Duty Mechanic
First Student Transportation
Riverside
07.2025 - Current
- Inspection, repairs, diagnostics on CNG, diesel, propane and gasoline powered school buses
- Diagnosing crank no starts/ no starts on cummins 8.9L cng and psi propane 8.8L engines
- Going on road calls/ service calls for stalled buses
- Diagnosing and repairing complex issues such as misfires for every cylinder simultaneously on cummins 8.9L cng engine
- Diagnosing and repairs on check engine lights
Heavy Duty Technician A Leader
Keolis Transit America
Irvine
06.2023 - 05.2025
- Assign work to technicans, create work orders on computer program Ellipse, update fleet hold list on excel spread sheet, update operations holdlist on DCS computer program
- Perform inspections and repairs on heavy duty cng transit buses
- Go on road calls. Make judegment on the road wether the transit vehicle that broke down can be repaired safely on the road or needs to be moved to a safe location. Make decision wether a tow truck is required
- Troubleshooting and repairs for electrical, engine, air conditioning, steering, suspension, brake, transmission related concers
- Complete front and rear brake replacement and hub rebuild for New Flyer Xcelsior buses
- Air dryer remove and replacement
- Oil and filter changes including engine, transmission, hydraulic, cng filters and fluids
- Rear main seal remove and replacement
- AC compressor remove and replacement
- Intake manifold removal and overhaul ( cleaning and sensor replacement if needed)
- Troubleshooting, diagnostics and repairs for CEL, SEL, check trans, AC fail, ABS fault, battery lights
- Troubleshooting and repairs for heavy duty charging system
- Remove and replacement EMP and oil cooled alternators
- Train technicians of class B, A, master
- Fuel cng transit buses
- Remove and replace radiators
- Diagnostics, Troubleshooting and repairs for Fan faults on EMP and greyson cooling fan system
- Diagnostics, trouble shooting and repairs for kidde fire/gas suppression system
Heavy Duty Technician Leader
First Transit, Inc.
Irvine
06.2019 - 06.2023
- Assign technicians work
- Train technicians of levels C, B, A, master
- Communicating with cencom/radio in the event of a yard accident, prior to a fire/ gas suppression test, road calls
- Providing incident reports to technicans that where involved in an accident, taking photos of accident, reporting accident to cencom and management team
- Inspecting and repairing heavy duty cng transit buses
- Front and rear heavy duty drum brake service
- Repacking wheel bearings and hubs with chasis grease
- Lubbing entire chasis of buses
- Replacing engine and transmission mounts
- Diagnostics and repairs on HVAC R 407C Thermoking system
- Diagnostics and repairs for cummins engine, allison transmission, TK hvac, electrical, brakes, steering, suspension, differential, emp/ greyson engine fan, 60-90 vanner, kidde fire/ gas suppression system related concerns
- Going on roadcalls
- Replacing all fluids and filters on a heavy duty transit bus
- Typing a detailed passdown towards the end of the shift and submitting to management team
- Verbally receiving and giving an in person detailed pass down with previous and the following shift supervisor or technician leader
- Replacing rear main seals
- Replacing TK screw type compressors
Heavy Duty Technician
CHTC Bus Group USA
Pomona
01.2019 - 06.2019
- Perform inspection and repairs on diesel tour buses
- Perform diagnostic and repairs for engine, transmission, air conditioning, steering, suspension, electrical concerns
- Go to road calls for broken down tour buses
Heavy Duty Technician A
MTA/ Metro
Los Angeles
03.2012 - 11.2018
- Fuel buses
- Perform inspection and repairs on cng heavy duty transit buses
- Rebuild cummins islg inline 6 engines( Complete inframe overhaul. New head, pistons, connecting rod bearings, piston sleeves etc)
- Rebuild Detroit Diesel 4 cylinder engines
- Go on road calls
- Tow buses
- Remove and replace differentals
- Remove and replace radiators
- Make swagelock cng lines for transit buses
- Troubleshooting, diagnostics and repairs for engine, transmission, air conditioning, steering, suspension, cng, electrical related concers
- Troubleshooting, diagnostics and repairs for CEL, SEL, check transmission, hot engine, abs, ac fault, bettery lights
- Remove and replace 50dn, emp, oil cooled alternators
- Filter and fluid changes
- Perform inspection and repairs on hubner joint for 60ft long transit buses
- Troubleshooting, diagnostics and repairs for kidde and amerex fire/ gas suppression system
Education
Certificate of Achievement Automotive Related Technology - Automotive
Los Angeles Trade Technical College
06-2014
Skills
- Experience in the following:
- Performing inspection and repairs on cng, diesel, propane, gasoline powered school, transit and tour buses
- rebuilding Cummins islg 89L and Detroit diesel engines
- Replacing rear main seals
- Replacing camshaft seals
- Replacing rear axle seals on heavy duty disc and drum axles
- Repacking grease on heavy duty wheel bearings, inspecting and replacing wheel barings and races
- Fault light diagnostics and repairs
- HVAC troubleshooting and repairs
- 608 universal certified
- ASE S4 certified
- R12, R134a, R407C refrigerants
- Using nitrogen to pinpoint refrigerant leaks on Thermoking AC systems
- IntelligAire 2 and 3 HVAC systems
- AR2700, RobinAir and Van Steenburgh refrigerant machines
- Performing oil changes on Thermoking AC compressors
- Performing engine oil, transmission oil, Differential oil changes with filter changes
- Replacing cng, diesel, propape, gasoline filters
- Diagnosing and replacing heavy duty differentials
- Diagnosing and replacing heavy-duty radiators
- Diagnosing and replacing Charge Air coolers
- Diagnosing and replacing Turbo chargers
- Diagnosing, condemning and replacing failed TK AC compressors
- Vansco and DINEX multiplex systems
- Cooling system, hydraulic and electrical fans
- Hydraulic systems
- Air compressors and air system
- Air dryer diagnosis and rebuild
- D2 governors diagnostics and replacement
- Heavy duty air brakes Drum and disc brake system inspection and repairs
- Steering/ suspension inspection and repairs, alignments
- Electrical diagnostics and repairs
- Repining deutch and weather pack connectors and pins
- J1939 communication system wiring troubleshooting and repairs
- Inspecting and repairing child check mate / theft alarm systems
- Computer programs such as Excel, Ellipse, Hexagon, Infor,DCS, Outlook, Microsoft Word
- Making work orders, charging out labor to work orders Closing work orders properly with detailed information such as notes, time, date, technician badge number When dealing with a road call work order, labeling wether a roadcall was valid or non valid prior to closing on infor, Hexagon and ellipse
- Working alongside and communicating with radio/ cental communication (cencom), dispatch operations
- Going on road calls/ service calls for buses broken down in the middle of intersections and freeways
- Heavy Duty Technician leader 5 year experience
- Installing drive cams and all the wiring included on transit buses, inspecting and repairing camera systems
- Transmission Allison B400r and B500r diagnostics and repair
- Diagnosing, condemning and replacing Allison B400r and B500r transmissions
- Cummins cng islg Engine diagnostics and repairs
- Diagnosing ECM harnesses, pinning out entire ecm harness, replacing ecm harness on cummins 89l cng engines
- Reading electrical schematics
- Heavy-duty transit diagnostic programs such as cummins insite, allison doc, wabco, emp, thermo king, can diag, vanner, JPRO
- Kidde and amerex gas/fire suppression, inspection, troubleshooting, diagnostics and repairs
- Typing a professional format passdown of everything that was accomplished on the shift Attaching snips of current transit fleet hold list to passdown and submitting to supervison/ management team via work email
- CNG tank inspection and repairs
- Making new air conditioning hoses, new cng lines, new air system hoses
- Transit wheel chair ramp inspection and repairs
- Training technicans of levels C,B,A, master
- Training heavy duty maintenance supervisors and technician leaders on computer program softwares, job duties and responsibilities
Affiliations
- I love the heavy duty transit industry, its my entire life
- Maintaing a strict and healthy diet
- Cycling
- Spending quality time with family and friends
- Teaching others, training coworkers and technicans in the heavy duty field. It's a very rewarding feeling
Certification
- 608 air conditioning universal certificate
- Certificate of achievement automotive related technology
- ASE S4 certificate
Languages
English
Spanish
References
References available upon request.
Timeline
Heavy Duty Mechanic
First Student Transportation
07.2025 - Current
Heavy Duty Technician A Leader
Keolis Transit America
06.2023 - 05.2025
Heavy Duty Technician Leader
First Transit, Inc.
06.2019 - 06.2023
Heavy Duty Technician
CHTC Bus Group USA
01.2019 - 06.2019
Heavy Duty Technician A
MTA/ Metro
03.2012 - 11.2018
Certificate of Achievement Automotive Related Technology - Automotive
Los Angeles Trade Technical College