Maintenance Mechanic

Subsidiary: Sully Miller Holding Co.


United Rock Products is one of the companies that operates within Sully-Miller Contracting Co., the Colas USA subsidiary that operates throughout Southern California. We are part of Sully-Miller Companies consisting of Sully-Miller Contracting Co., Blue Diamond Materials and United Rock Products. Each company supports the other. United Rock provides the aggregate, Blue Diamond Materials provides the hot and warm mix asphalt manufacturing, and Sully-Miller Contracting executes the projects. Mining of construction aggregates at United Rock Products in the San Gabriel Valley has taken place since 1916. Our top-rated 300-acre site is located in Irwindale, California, just 25 miles east of Los Angeles. Virgin aggregate material is processed into sand and gravel through cutting-edge crushing and screening operations. To learn more about United Rock Products visit

Throughout Colas USA, we provide competitive pay, outstanding benefits, career advancement opportunities, professional education, and extensive training for every employee. We pride ourselves on upholding the highest standards of safety, environmental conservation, and ethical conduct as we strive to grow our infrastructure products and services through empowering and developing our people, fostering innovation, utilizing new technology, and maximizing vertical integration at all levels of the company’s value chain. To learn more about the Colas USA Family of Companies, please visit

United Rock Products, and the rest of the Colas USA Family of Companies, is part of the Colas Group, the worldwide leader in transportation infrastructure construction and maintenance. For information on our international network visit

Job Summary


Under the supervision of the Maintenance Foreman and/or Site Manager, the Maintenance Mechanic is responsible to work independently on all maintenance and repair tasks within the aggregate plant. 

Main Responsibilities



  • Examines and diagnoses problems, and repairs according to generally accepted methods.  Discusses extensive or difficult in depth repairs with Foreman and/or Site Manager.  
  • Performs routine scheduled maintenance as outlined by the Foreman and/or the Site Manager 
  • Removes components for repair or replacement such as, but not limited to; motors, gearboxes, pulleys, bearings, rollers, conveyor belts, v-belts, pumps, screens, crushers etc. 
  • Disassembles components, inspects parts for wear, and determines cause of failure. 
  • Troubleshoots and repairs hydraulic systems, and components. 
  • Inspects and replaces parts such as crusher liners, screen media, etc. 
  • Overhauls or rebuilds serviceable components 
  • Performs major welding and cutting -- must pass a welding/cutting test (certification strongly preferred). 
  • Replaces and or repairs chute liners/wear plate, able to fabricate steel in or out of the field for proper fit.  
  • Recommends parts for repair 
  • Perform post repair verification/start up  
  • Will perform clean-up as necessary to keep tools, equipment, and working areas clean, orderly, and safe. 
  • Other duties as assigned by the Foreman and/or Site Manager  



Colas Inc. and its subsidiaries (United Rock Products) are an Equal Opportunity Employer. For details on the specifics of this commitment, please click here to view the EEO document. If you need an accommodation to access the information provided on this website, please contact Colas Inc. 973-290-9082 or send an email to

Nearest Major Market: Los Angeles