Senior Diesel Technician - Heavy Truck & Hydraulic Systems

Job Description

Job Description

Step into a day where big iron meets bigger impact

When the first commercial truck rolls into the bay, you connect diagnostics, listen to the engine note, and map out the repair plan. By mid-morning, you’re rebuilding a brake assembly; after lunch, you’re chasing down an intermittent 24V electrical fault, and before the day ends, you button up an EGR cooler service on a Class 8 tractor. That’s a typical day for a Senior Diesel Technician at Custom Truck One Source (CTOS)—a 30+ year industry leader with 40+ locations, 2,600 employees, and a 10,000+ unit fleet serving the utility, telecom, rail, and construction markets.

The role

Join our service team to perform full-lifecycle maintenance, diagnostics, and repairs across a diverse fleet of commercial trucks and heavy equipment. We’re looking for a technician with deep, bumper-to-bumper knowledge and the reliability to see every job through safely and correctly.

What you’ll tackle

• Advanced diagnostics: Use OEM and aftermarket software and tools to pinpoint mechanical, hydraulic, and electronic issues.
• Chassis and powertrain: Inspect, repair, and overhaul steering, suspension, brakes, and driveline components.
• Emissions systems: Service critical components with emphasis on EGR systems, coolers, and valves.
• PTO and hydraulics: Install, troubleshoot, and repair PTO gearboxes and integrated hydraulic systems (pumps, cylinders, valves, winches).
• Electrical: Interpret schematics to diagnose and repair complex 12V/24V circuits, wiring harnesses, starting/charging systems, and control modules.

What you bring

• Valid Driver’s License; CDL is a plus.
• Hands-on experience as a Diesel Mechanic on Class 6, 7, or 8 heavy trucks.
• Proven mechanical aptitude with a strong safety-first mindset and compliance focus.
• Graduates of vocational/technical programs and military veterans with mechanical training are strongly encouraged to apply.

Proficiencies that set you apart

• Heavy equipment repair and diesel/heavy equipment systems
• Hydraulic systems, PTO and auxiliary systems
• Light vehicle diesel engines
• Electrical systems and diagnostics (12V/24V, heavy equipment)
• Crane and lifting systems; aerial and utility equipment systems
• DOT and equipment inspection compliance

Rewards and growth

CTOS offers competitive pay based on skills and experience, paid vacation, sick time, and holidays, a 401(k) match, healthcare, dental, vision, and prescription coverage, uniforms, boot allowance, ongoing training, and more.

Equal Opportunity Employer