Abstract: An anti-skid power valve means for brake control apparatus, which valve means connects a pressure supply line to a wheel brake system, the valve means including a piston operably positioned in a chamber means, and a check valve means operably carried by the piston to cause flow of liquid from the wheel brake system to the pressure supply line when the piston is driven. Other means connect the pressure supply line to the wheel brake system and include a flow control orifice therein to permit by-pass liquid flow from the pressure supply line to the wheel brake system.