A valve (60) for use in a brake system (10) through which a source (32) of fluid charges an accumulator (24) to a desired fluid pressure level and through which fluid pressure present in a conduit (52) is communicated to a reservoir (33) in the absence of the flow of fluid from the source. The valve (60) has a housing (62) with a bore (64) therein with an entrance port (66) connected to the source of fluid (32), an exit port (68) connected by a flexible conduit (52) to the accumulator (24) and exhaust port (70) connected to the reservoir (33). A sleeve (72) which is located in bore (64) has an internal bore (74) with a first diameter (82) for retaining a first ball (90), a second diameter (80) for retaining a linkage member (94) and a third diameter (86) for retaining a second ball (92). The communication of fluid from the source (32) to the entrance port (66) developing a force across the sleeve (72) which moves the second ball (90) into engagement with an exhaust port (70) to interrupt communication to the reservoir (33) and allow fluid to flow from the entrance port (66) to the exit port (68) for charging the accumulator (24).