Overhaul

Fig. 40 Exploded View Of Power Steering Pump:

1. Disassemble power steering pump in numbered sequence shown, Fig. 40. Secure pulley with tool No. MB990767, or equivalent, when removing mounting nuts.
2. Reverse numbered sequence to reassemble, noting the following:
a. Install oil seal using installation tool Nos. MB990938 and MB991203, or equivalents.
b. Apply Dexron II or Diamond ATF SP ATF to all O-rings prior to installation.
c. Install rotor on shaft with punch mark at pump cover side.
d. Install cam ring with punch mark facing pump cover.
e. Install rotor vanes with rounded edges facing cam ring.
f. Secure pulley with tool No. MB990767 and spacer tool No. MD998719, or equivalents, when installing pulley locknut.
3. Inspect flow control valve for clogging, shaft for damage or excessive wear, rotor and vane groove for "stepped" wear and vanes for damage.
4. Measure clearance between shaft and oil pump body using a suitable micrometer and caliper gauge as follows:
a. Measure inside diameter of oil pump body bore, then measure outside diameter of shaft.
b. Subtract shaft diameter from oil pump body bore diameter to obtain clearance measurement. Clearance should not exceed 0.0276 inch.