Disassembly (Model P)

Drain pump reservoir. Clean exterior of unit. Using Puller (J-29785-A), remove pulley from shaft if not previously removed.
Remove pressure line union and "O" ring. Remove reservoir retaining bolts. Remove reservoir and "O" rings from housing.
Using punch and screwdriver, remove end plate retaining ring. Remove end plate and pressure plate spring. See Fig 1 .
Remove "O" ring, flow control valve, and spring. Using soft-faced hammer, tap end of drive shaft to loosen pressure plate. Remove pressure plate, pump ring, vanes, retaining ring, rotor, and thrust plate assembly from body.
Remove drive shaft. Using a screwdriver, pry drive shaft oil seal from housing. Remove dowel pins and seals.

Fig 1: Exploded View of Pump Assembly (Model P)

Courtesy of GENERAL MOTORS CORP.