Section 8 - Cooling System - Group 08 Water Pump - Rebuild (8-02) M11 Page 8-19 The flat side of the retainer ring must be installed toward the bearing. Use a pair of snap ring pliers to install the bearing retainer ring into the groove on the shaft. The sealing lip of the oil seal must be installed toward the seal driver. Install the oil seal on the water pump oil seal driver, Part No. 3376139. Install the water pump body in an arbor press with the oil seal bore (water pump mounting surface) facing up. Install the oil seal and oil seal driver into the oil seal bore. Press the oil seal into the oil seal bore until the seal driver contacts the water pump body. Do not lubricate the oil seal.
The oil seal must be installed with the lip of seal and the shaft clean and dry to provide a proper sealing surface and prevent future water pump and engine damage. Install the water pump oil seal expander, Part No. 3376387, on the impeller end of the shaft.