The operator of a water cart had noticed a strange smell and returned to the workshop.
An inspection did not identify any issues.
The truck left the workshop heading to a dump when the operator noticed a loss of power and saw smoke in the rear mirrors.
The truck was immediately parked up.
Flames then started coming from the engine bay around the front of the truck.
The fire was extinguished by other water carts.
The operator complained of breathing issues and was taken to hospital.
The NSW Resources Regulator said that after being assessed, the worker was released and returned to the mine to complete their shift.
"Maintenance systems must be comprehensive and consider all reasonably foreseeable risks of fire or explosion," it said.
"When operators report defects or concerns, thorough inspection and testing should be conducted to ensure the plant is safe to operate."
