A system for cooling a reductant injector in an emissions module is provided. The system includes an emissions module, coupled to an engine exhaust duct, and a cooling system fluidly coupled to the emissions module. The emissions module includes a reductant system and a selective catalytic reduction (SCR) module. The reductant system includes a reductant injector having a cooling passage. The cooling system includes a reservoir tank, a supply pump fluidly coupled to the reservoir tank, and a siphon tank fluidly coupled to the supply pump and the reductant injector cooling passage. The siphon tank is disposed proximate to the reductant injector, and a gravitational elevation of a base of the siphon tank is greater than a gravitational elevation of the reductant injector.