GM Service Manual Online
For 1990-2009 cars only

Object Number: 313979  Size: SH

The hydraulic pump is a vane-type pump. The fluid reservoir may be separate from the pump depending on the engine application.


Object Number: 313977  Size: SH

There are 2 bore openings at the rear of the pump housing. The larger opening contains the following components:

    • The cam ring
    • The pressure plate
    • The thrust plate
    • The rotor
    • The vane assembly
    • The end plate

The smaller opening contains the following components:

    • The pressure line union
    • The flow control valve
    • The spring

The flow control orifice is part of the pressure line union. The pressure-relief valve inside the flow control valve limits the pump pressure.