A hydraulic system for an implement coupler assembly of a machine includes a coupler cylinder, a control valve connecting the coupler cylinder to a pressurized fluid source and a low pressure reservoir, and a sequence valve and a check valve connected in parallel between the coupler cylinder and the control valve. An implement cylinder provides a pilot pressure for the sequence valve. The coupler cylinder extends to a locked position when the control valve provides pressurized fluid through the check valve to a head end of the coupler cylinder. The coupler cylinder retracts to an unlocked position when the control valve provides pressurized fluid to a rod end of the coupler cylinder if the implement cylinder provides pilot pressure sufficient to open the sequence valve and connect the head end of the coupler cylinder to the low pressure reservoir.