摘要 |
A vehicular hydraulic braking pump includes a sleeve having an inner bore defining an inner bore surface and a piston having a stop collar and a ramped seal face. The stop collar, ramped seal face, and the inner bore cooperating to define a seal pocket which traps a high pressure seal therein. The ramped seal face provides contact of the high pressure seal to the sleeve inner bore that is proportional to fluid pressure acting on the high pressure seal. |