Power Steering - Power-Assisted Recirculating Ball: Overhaul: Disassembly

Press cover in slightly and remove retaining ring. Remove cover, coil spring and "O" ring. Remove end plate and "O" ring, noting location of pin in one of the small holes in end plate.
Tilt housing and remove cam ring and rotor. Note that side of rotor with recessed hole faces drive shaft, the rounded off side of rotor faces cam ring, and the cast-in half arrow indicates direction of rotor rotation.
Remove drive end face plate and "O" ring. If it should be necessary to remove input shaft, proceed as follows: Remove pulley, shaft seal, and snap ring from housing.

Fig 1: Pin Location Inside Of Pump Housing
Courtesy of BMW OF NORTH AMERICA, INC.

Note which hole pin is located in when disassembling.
Remove circlip and press ball bearing off of shaft. Using a mandrel, press bearing sleeve out of housing.
Remove plug from pressure valve bore. Remove coil spring and valve piston. Note that threaded section on valve piston faces coil spring.

Fig 2: Mark Showing Direction Of Rotation
Courtesy of BMW OF NORTH AMERICA, INC.

The rounded off side of rotor faces cam ring.

CAUTION: Do not alter length of coil spring or thickness of plug sealing ring.
The valve tolerance group (1 or 2) is stamped into housing adjacent to pressure valve bore and valve barrel should be scribed with one or two marks (lines) agreeing with group number stamped into housing.
NOTE: If valve must be replaced, install valve of same tolerance group.

CAUTION: When disassembling piston, do not clamp across sliding surfaces.
Clean and inspect all parts. Clean restrictor insert in pump outlet passage. Valve piston may be disassembled for cleaning. A pressure valve is located inside valve piston (flow limit valve).
Thickness of washers determines cut-in range of pressure valve. Maximum pump pressure should not be more than 10% below value stated on plate attached to pump.