Vehicle brake system

A brake system with a wheel brake has a fluid reservoir and a valve assembly in fluid communication with the reservoir via a first conduit. The valve assembly is in fluid communication with the wheel brake via a second conduit. The valve assembly includes a bypass valve which only permits fluid flow from the first conduit to the second conduit when the fluid pressure within the first conduit is above a predetermined pressure level above atmospheric pressure. The valve assembly further includes a check valve in a parallel path arrangement relative to the bypass valve such that the check valve permits fluid flow from the second conduit to the first conduit, and prevents fluid flow from the first conduit to the second conduit. The brake system further includes a first source of pressurized fluid providing fluid pressure for actuating the wheel brake, wherein the first source of pressurized fluid is selectively in fluid communication with the second conduit.