Valve system for selective control of drilling fluid flow

A downhole tool for forming a wellbore, comprising:

• one or more jets configured to flow a main flow of a flow of drilling fluid out of the downhole tool along a main flow path of the main flow;
• a main valve in fluid communication with the one or more jets along the main flow path and being actuatable to control the main flow through the one or more jets, wherein the main valve is actuatable based on a control flow of the flow of drilling fluid;
• an engagement actuator being actuatable based on the control flow to adjust a direction of the downhole tool;
• a control valve in fluid communication with the main valve and the engagement actuator along a control flow path of the control flow and configured to direct the control flow to the main valve and to the engagement actuator to actuate the main valve and the engagement actuator based on a mechanical input to the control valve;
• and
• a mechanical input mechanism for providing the mechanical input to the control valve.

A downhole tool for forming a wellbore, comprising:

• one or more jets configured to flow a main flow of a flow of drilling fluid out of the downhole tool along a main flow path of the main flow;
• an engagement actuator being actuatable based on the main flow to adjust a direction of the downhole tool;
• a main valve in fluid communication with the one or more jets and with the engagement actuator along the main flow path and being actuatable to control the main flow to the engagement actuator and to the one or more jets, wherein the main valve is actuatable based on a control flow of the flow of drilling fluid;
• a control valve in fluid communication with the main valve along a control flow path of the control flow and configured to direct the control flow to the main valve to actuate the main valve based on a mechanical input to the control valve;
• and
• a mechanical input mechanism for providing the mechanical input to the control valve.