Product Overview

Summary: This Cooling System Flush Safe Operating Procedure provides a clear, step-by-step method for safely draining, flushing and refilling cooling systems in plant, vehicles and fixed equipment. It helps Australian workplaces control chemical, thermal and pressure-related risks while maintaining equipment reliability and compliance with WHS obligations.

Cooling system flushing is a routine maintenance activity that, if done poorly, can result in burns, chemical exposure, environmental contamination and costly equipment damage. This SOP sets out a structured, repeatable process for safely isolating, depressurising, draining, flushing and refilling cooling systems in vehicles, mobile plant, generators, compressors and fixed plant. It clearly defines when a flush is required, who is authorised to perform it, and the controls that must be in place before any work begins.

Developed for Australian conditions and regulatory expectations, the procedure addresses real-world workshop and field risks such as hot coolant discharge, incompatible coolants, slips on spilled fluids and uncontrolled release of pressure. It also tackles business issues such as premature component failure, overheating events and unplanned downtime that arise from inconsistent maintenance practices. By implementing this SOP, organisations can demonstrate due diligence under WHS legislation, standardise technician practices across sites, and protect both workers and assets through a documented, defensible system of work.

Key Benefits

• Ensure cooling system maintenance is carried out safely, consistently and in line with WHS requirements.
• Reduce the risk of burns, chemical exposure and slips caused by uncontrolled coolant release and spills.
• Extend equipment life by preventing corrosion, scale build-up and overheating through correct flushing practices.
• Minimise unplanned downtime and costly repairs by standardising inspection and testing during each flush.
• Demonstrate due diligence and regulatory compliance with documented procedures, records and environmental controls.

Who is this for?

• Workshop Supervisors
• Heavy Vehicle Mechanics
• Automotive Technicians
• Maintenance Fitters
• Fleet Managers
• Plant and Equipment Supervisors
• WHS Advisors and Officers
• Facilities and Maintenance Managers

Hazards Addressed

• Thermal burns from hot coolant and engine components
• Exposure to hazardous chemicals in coolants and flush agents (skin contact, inhalation, ingestion)
• Pressurised system release causing sudden discharge of hot fluid or components
• Slips, trips and falls from spilled coolant and wet surfaces
• Manual handling strains from moving radiators, hoses, drums and flushing equipment
• Contact with moving parts if isolation and lock-out are not correctly applied
• Environmental contamination from incorrect disposal of waste coolant and flush solutions
• Fire risk where flammable cleaning agents or nearby ignition sources are present
• Eye injuries from splashes during draining, bleeding and pressure testing

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Abbreviations
• 3.0 Roles, Responsibilities and Competency Requirements
• 4.0 Applicable Legislation, Standards and References
• 5.0 Tools, Equipment, Materials and Documentation
• 6.0 Personal Protective Equipment (PPE) Requirements
• 7.0 Pre-Task Planning and Risk Assessment (JSA/SWMS)
• 8.0 Plant Isolation, Lock-out and Verification of Zero Energy
• 9.0 Cooling System Inspection and Pre-Flush Checks
• 10.0 Draining the Cooling System – Safe Work Steps
• 11.0 Flushing Procedure – Circulation, Cleaning Agents and Rinse Cycles
• 12.0 Refill Procedure – Coolant Selection, Mixing and Bleeding Air
• 13.0 Post-Flush Testing, Leak Checks and System Verification
• 14.0 Spill Management, Waste Handling and Environmental Controls
• 15.0 Emergency Procedures and First Aid for Burns and Chemical Exposure
• 16.0 Housekeeping and Return to Service
• 17.0 Record Keeping, Tagging and Maintenance Scheduling
• 18.0 Training, Competency and Review of Procedure

Legislation & References

• Work Health and Safety Act 2011 (Cth) and relevant state and territory WHS Acts
• Work Health and Safety Regulations 2011 (Cth) and equivalent state and territory regulations
• Safe Work Australia – Code of Practice: Managing risks of plant in the workplace
• Safe Work Australia – Code of Practice: Managing risks of hazardous chemicals in the workplace
• AS/NZS 4024.1201: Safety of machinery – General principles for design – Risk assessment and risk reduction
• AS 1940: The storage and handling of flammable and combustible liquids (where solvent or flammable flush agents are used)
• EPA and local environmental protection guidelines for storage, handling and disposal of waste coolant and chemicals