Field Service Mechanic - Heavy Duty Work Trucks

Assembly Systems, Inc.; Fresno (CA); Hybrid; USD 55,000 - 62,000; Full time

Benefits offered by this job

Uniforms provided

Tuition assistance

Health, dental and vision coverage

Paid Time Off

401(K) with company match

Long Term Disability

Short Term Disability

Life Insurance

Healthiest You

PPE Reimbursement

Pet Insurance

Employee Discounts

Employee Assistance Program

Health and well-being screening

Job summary

Interstate Assembly Systems is seeking a Field Service Mechanic to support heavy‑duty work trucks across the Central California region, including Fresno. You will troubleshoot, repair, and service mechanical, hydraulic, electrical, and pneumatic systems in the field.

The role requires hands‑on expertise, with extensive daily travel and potential overnight trips. A company vehicle, laptop, and phone are provided to enable responsive client service.

Qualifications

• Minimum of 3–5 years of experience as a mechanic working on heavy‑duty trucks or equipment.
• Proven expertise in repairing hydraulic systems, cranes, welders, and air compressors.
• Strong knowledge of diesel engines, electrical systems, and heavy‑duty vehicle diagnostics.
• Welding and fabrication skills (e.g., MIG, TIG, stick welding) preferred.
• Ability to read and interpret technical manuals, schematics, and diagnostic codes.

Responsibilities

• Conduct routine maintenance and inspections on heavy‑duty work trucks and their integrated systems (cranes, welders, air compressors, etc.).
• Diagnose and repair mechanical, hydraulic, electrical, and pneumatic issues on trucks and attached equipment.
• Perform welding and fabrication tasks as needed to repair or modify truck components.
• Operate and test cranes to ensure proper functionality and safety compliance.
• Service and maintain air compressors and other auxiliary equipment.
• Respond to client service calls in the field, providing timely and effective solutions.
• Document all service work, including parts used, time spent, and detailed repair notes.
• Adhere to safety standards and regulations, including OSHA and DOT requirements.
• Collaborate with clients to explain repairs and provide recommendations for preventative maintenance.

Skills

Troubleshooting

Diesel engine knowledge

Electrical systems

Tools

Hydraulic systems

Cranes

Welders

Air compressors

Job description

Interstate Assembly Systems has excellent opportunities for individuals looking for challenging careers with exciting growth potential and competitive benefits. We’re a growing vehicle upfitter and Tier 1 product assembler. Our areas of expertise include contracted assembly and related services including integration, logistics, procurement, and process control as well as all aspects of vehicle upfitting.

Our assembly team members display strong skills in areas such as manufacturing, warehouse, shipping and receiving. Our vehicle upfitting team skills range from welding, painting and mechanical to parts specialists and service technicians.

• Broad range of health insurance options
• Flexible time off
• 401(k) retirement plan with up to 25 percent company match

Other Perks

• Membership banking with Wells Fargo
• Dell discount program
• New vehicle discount programs with General Motors, DaimlerChrysler and Ford

Open Positions at Interstate Assembly Systems

Field Service Mechanic - Heavy Duty Work Trucks

Job Title: Field Service Mechanic – Heavy Duty Work Trucks
Position Location & AOR: Fresno, CA (150 Mile working radius)
Company: Interstate Assembly Systems
Pay Range: $40.00 - $45.00 / Hour D.O.E.

We’re looking for a skilled and motivated Field Service Mechanic to join our team and keep our clients’ fleets running at peak performance This role requires a hands‑on professional who can troubleshoot complex mechanical, hydraulic, and electrical issues in the field, ensuring minimal downtime for our clients working in the Central California region. (150 Mile radius of Fresno, CA)

A company service vehicle, laptop and cell phone will be provided with this position.

This position requires extensive daily travel to customer job sites, with travel time potentially reaching up to seven hours per day. Occasional overnight travel may be necessary based on business and customer needs.

Interstate Assembly Systems is a leading provider of heavy‑duty work truck solutions, serving industries such as construction, mining, utilities, and more. We specialize in custom‑built service trucks equipped with cranes, welders, air compressors, fuel and lube tanks and reels, hydraulics, and other advanced systems.

Key Responsibilities

• Conduct routine maintenance and inspections on heavy-duty work trucks and their integrated systems (cranes, welders, air compressors, etc.).
• Diagnose and repair mechanical, hydraulic, electrical, and pneumatic issues on trucks and attached equipment.
• Perform welding and fabrication tasks as needed to repair or modify truck components.
• Operate and test cranes to ensure proper functionality and safety compliance.
• Service and maintain air compressors and other auxiliary equipment.
• Respond to client service calls in the field, providing timely and effective solutions.
• Document all service work, including parts used, time spent, and detailed repair notes.
• Adhere to safety standards and regulations, including OSHA and DOT requirements.
• Collaborate with clients to explain repairs and provide recommendations for preventative maintenance.

Qualifications

• Minimum of 3-5 years of experience as a mechanic working on heavy-duty trucks or equipment.
• Proven expertise in repairing hydraulic systems, cranes, welders, and air compressors.
• Strong knowledge of diesel engines, electrical systems, and heavy-duty vehicle diagnostics.
• Welding and fabrication skills (e.g., MIG, TIG, stick welding) preferred.
• Ability to read and interpret technical manuals, schematics, and diagnostic codes.
• Valid driver’s license required; CDL (Commercial Driver’s License) is a plus.
• Comfortable working independently in the field and in various weather conditions.
• Excellent problem-solving skills and attention to detail.
• Physical ability to lift to 50 lbs. and work in confined spaces as needed.
• Certification in crane operation, welding, or heavy equipment repair is an advantage.

Employee Benefits

• Uniforms - fully supplied by Interstate!
• Tuition assistance - for educational and ongoing career growth
• Health, dental and vision coverage - begins on the first day of the following month.
• Paid Time Off - (PTO) starts accruing day one of your full-time employment.
• Holidays - 6 Holidays and 2 Floating Holidays per year
• 401(K) - with company matching.
• Long Term Disability - Supplied
• Short Term Disability - Supplied
• Life Insurance - Supplied
• Healthiest You - Virtual Health Care paid by Interstate.
• PPE Reimbursement - Safety Glasses and Safety Boot Reimbursement
• Pet Insurance – We care about our furry friends!
• Employee Discounts - available on products and services
• Paid Employee Assistance Program - Free 24/7 Access to a guidance consultant regarding life challenges you or family member may face.
• Paid Health and Well-being screening - for employees and their spouse

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities, and activities may change at any time with or without notice.

Interstate Companies is an Equal Opportunity Employer, and we encourage all qualified and interested persons to apply for this position by submitting a resume for consideration.