This SAE Standard applies to direct acting hydraulic power assist brake boosters only, of the type which provide "push through" manual braking of the static brake circuit(s) via a separate master cylinder, in event of inoperative power assistance similar to existing vacuum boosters (SAE J1808), for passenger cars and light trucks [4500 kg GVW (10 000 lb)].
This document specifies minimum test standards for direct acting hydraulic power assist brake booster of current established designs utilizing mineral oil based hydraulic fluids. It is applicable to assemblies from commercial production and after production shipment.
This procedure is applicable to existing hydraulic powered brake boosters of a design which is still in current production but for which there have been no significant changes in many years. It is not expected that the type of unit covered by this procedure will be redesigned. The current state of the art of non-vacuum power assist units involves technology not covered by this procedure.